I bought a couple of things and found this combo to work the best:

Cable: https://www.amazon.com/gp/aw/d/B01BFJ0FX6

Digital Audio Recorder:
https://www.amazon.com/Sony-ICDUX560BLK-Stereo-Digital-Recorder/dp/B01FWNSXJO/ref=mp_s_a_1_5

No need for a phone or to record with a GoPro.

Looks great! I like your use of natural audio in the beginning of the video too. Making sure you get good audio/having some backup sources is definitely one of the harder parts of wedding videography, but once you make one mistake I bet you won't make it again! For the ceremony I bring my own lapel mics, mic up the groom, the officiant, and plug into the soundboard/speaker if there is one available. These Sony recorders are so clutch, the battery lasts for ever and theyre really tiny so you plug a lapel mic direct into it and slip it in the grooms jacket pocket.

I would've liked to hear audio from those speeches at the reception. Don't know if you plugged into the DJs soundboard or not but that's something I would do going forward. Also, make sure you have about every audio cable possible because you never know what the DJ or band will have for you. Usually it's either XLR or RCA but I do get the occasional band that has a 1/4" input for me. Make friends with the sound guy/DJ when you arrive, it goes a long way. Backup sources are key here as well.
Don't know if you've watched any Matt Johnson videos on YouTube but he has some extremely informative videos for wedding videographers including this one about audio: https://www.youtube.com/watch?v=SSJKxcfFagE&

Anyway, keep up the great work you have a lot of skill, and for your first video it really looks awesome! Best of luck in the future!

The iPhone is an option, but I wouldn't necessarily trust it to record quality audio all the time, or not stop accidentally recording.

Instead, you can get a set of dedicated audio recorders for this. At your budget, I wouldn't go with wireless. A good budget option will be a Sony audio recorder [referral link] with a lavalier microphone. A few of those at $110 a set should be good, but you can also choose a different 3.5mm microphone if you want. They have 4GB of internal space, and can be expanded with a microSD card. They also have a lock mode so they won't accidentally stop recording, and they're very slim so they can easily fit in a pocket.

Mods: Please remove if too self-promo-y!

I just got back from Podcast Movement, where I was mainly engulfed by creators trying to min/max their show--which is fine--but that's not how I prefer to think about things.

So I made a quick video highlighting the tools & workflow choices I've made to optimize for quality AND speed.

Brief Rundown:

Organization:

Make a new folder for each new episode! Interview, solo show, doesn't matter--we deal with tons of files and this will help save brain cells.

Recording:

• Voiceover/solo shows when at computer = Straight into Hindenberg Journalist Pro
  
• Interviews = Up until two weeks ago, Skype + Ecamm Call Recorder. Currently using Zencastr (but looking at Squadcast as well!)
  
• Remote = Sony 1" Recorder (not an affiliate link) with a cheap Lav.
  
  Note: I JUST received a nice USB adapter hub for my 2018 iPad Pro--which finally lets me use a nice USB mic (ATR2100 in my case) more regularly--so I'm looking to do more recording via iPad on the AUM and Audioshare apps).
  
  Editing:
  
  I used to edit in Logic Pro, then Hindenberg, and now Ferrite (on iPad Pro with Apple Pencil 2nd Gen).
  
  I airdrop audio files to iPad (it gives me the option to open directly with Ferrite), then strip silence and begin editing (ums, stutters, extended silence, etc).
  
  I then share each track separately in .wav format BACK to the Macbook Pro, and add to a "save as template" Hindenberg Journalist Pro.
  
  From there I will drag-n-drop my podcast intros (from Hindenberg's favorites bar--SO GOOD), arrange and time tracks, etc.
  
  Mixing:
  
  Again, I'm mostly trying to hit a nice threshold for "listenability!" Most podcast engineers might murder me at this point.
  
  I have the following plugins pre-loaded on each track.
  
  
• iZotope RX7 Noise Reducer
  
• Wave Debreath
  
• iZotope Neutron (for EQ and light compression)
  
• iZotope Nectar (for magic "oh this sounds way more clear now")
  
  That's really it. Hindenberg normalizes audio and allows exports to -16 LUFS podcast standards.
  
  Publishing:
  
  I use Podbean for hosting, because of the cheap unlimited minutes, and because it works. Never had a single issue in 2.5 years of hosting.
  
  I use Otter.ai for transcripts (It generally takes me about 30 minutes to get through a 60-90 minute interview. Much less for solo shows). I then copy/paste into a pre-made HTML <div> in my shownotes.
  
  Watch the video for more context on that.
  
  I also use TextExpander for a hotkey generated "embed box" HTML in WordPress. See video for that as well.
  
  Other stuff I love for speedy podcasting:
  
  Auphonic. As far as speed goes, you can't beat it.
  
  Levelator. Underrated little plugin! Mostly just normalizes loudness I believe. I'm also going to assume this plugin will work forever until the end of time. I feel like people have been saying otherwise for years?
  
  That's it!
  
  I hope somebody gets a nugget of use out of this :)

Use this for lav.

https://www.bhphotovideo.com/c/product/1281085-REG/tascam_dr_10l_mini_portable_recorder.html

It's a little more than your cheapest option, but it is worth it for quality, size, and ease of use. You'll need at least 2-3 for weddings.

Use this recorder to take a line out from the DJ or band.

https://www.bhphotovideo.com/c/product/821259-REG/Tascam_DR_40_DR_40_4_Track_Handheld_Digital.html

I think this is the best cheap option, especially because it can record a lower-volume safety track. You will need cables to connect as well. You can also put this mic on a podium or speaker for a backup.

I an emergency, an iPhone is better than nothing. I would get a mic to improve quality. I used the Shure MV88 and was surprised with the quality.

We use this for a backup.

Sony ICDUX560BLK Stereo Digital Voice Recorder with Built-in USB https://www.amazon.com/dp/B01FWNSXJO/ref=cm_sw_r_cp_api_ABGSzbSGS59JG

We use an elastic sleeve to attach this small recorder directly to the microphone used for speeches/toasts. This backup has saved us several times.

It is confusing to figure out what works. I ended up getting a "Sony ICDUX560BLK Digital Voice Recorder 1" Black" that I can backup and restore from. Don't have it on me right now... But I believe I just had to set it to 44khz. Pretty sure you need something that can record 16 bit stereo at that frequency

Sony ICDUX560BLK Digital Voice Recorder 1" Black https://www.amazon.com/dp/B01FWNSXJO/ref=cm_sw_r_cp_apa_i_vmU3DbVBFG50Y

Sony ICDUX560BLK Digital Voice Recorder 1" Black https://www.amazon.com/dp/B01FWNSXJO/ref=cm_sw_r_cp_apa_i_EpBIDb3NRSHH6
^ This is what I use, I've never had a problem with it. Keep it peeking out of my backpack on the ground

Sony ICD-PX470 Stereo Digital Voice Recorder with Built-in USB Voice Recorder https://www.amazon.com/dp/B06XTX2S2N/ref=cm_sw_r_cp_apa_i_vqBIDb1WX15P8
^cheaper version

Thanks so much for the advice. Good point about the lav. I hadn't thought about that.

Unfortunately I don't really have the budget for the preamp or that DR-60, but I'll definitely bookmark them for later.

So that I can save the H1 for a different use, would this work for the lav? It's skinnier too, so sliding it into the grooms pocket would be easier.

The proper mixer setup is also something I hadn't thought about. The events I've done in the past were all pretty amateur. The entire sound system was just a mic plugged into one big speaker setup and the music was played through the same, so there weren't different outputs. A real DJ would have different lines for music and mics and all, right? So the extra inputs would all be from the DJ himself. Ok now I see where that would be helpful.

This looks pretty useful.

https://www.amazon.com.au/Sony-ICDUX560BLK-Stereo-Digital-Recorder/dp/B01FWNSXJO/ref=asc_df_B01FWNSXJO/?tag=googleshopmob-22&linkCode=df0&hvadid=341743199244&hvpos=1o1&hvnetw=g&hvrand=4613825417418571314&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9071660&hvtargid=pla-403917579267&psc=1