Reddit mentions of BIQU Aluminum Raspberry Pi 4B/4B Plus Case Enclosure Box (Grey)

Go one step further, make the case the heatsink.

I haven't heard any word about 4.3 coming out, but updating is very easy from within retropie.

Some stuff from an old post that is applicable here:

Don't waste your money on the heat sinks, they don't do much without a fan. The nintendo case is cool, and it will work for the NES emulation, but it will not cut it for N64, since you'll probably overheat with an overclock. Overclocking is basically required for N64 to run even sorta smooth. Instead, get a better case that can handle heat effectively. I use https://www.amazon.com/BIQU-Aluminum-Raspberry-Case-Enclosure/dp/B01H8L4EM8; but others have used a Flirc with great success: https://www.amazon.com/Flirc-Raspberry-Case-Gen2-Model/dp/B07349HT26/ref=sr_1_3?s=electronics&ie=UTF8&qid=1500310306&sr=1-3&keywords=flirc.

It's worth going for function over form in this scenario.

As for other advice/tricks for setup:

1. Install this mod to minimize errors where phanton controllers and keyboards end up in the player 1 slot: https://github.com/meleu/RetroPie-joystick-selection/blob/master/README.md
   
   
2. Set up WinSCP and SSH to transfer roms easily: https://www.youtube.com/watch?v=fsRkTlv5rxw
   
   
3. Swag polish:
   
   Get video previews set up: https://www.youtube.com/watch?v=AqIu1whpw_M
   
   Get slick loading splash screens set up when you start a game: https://www.youtube.com/watch?v=_aXerbx4TpA
   

>every other case will fit a 3B and 3B+ the same because the external form factor is identical.

No one is contesting that point.

I had a similar setup, but using a generic chinese 5V fan with a simple circuit to start/stop the fan via python, which kept my board at a cool ~ 35'C . Alas, the fan proved to be noisy (I'm sure your Noctua is a lot more quiet) and I went with a BiQU passive cooling case for my Raspi 3B Plus which keeps my board at a ~41'C temp at 26'C ambient temp.

Be warned, if you plan on using the case, you will need to file down its aluminium heatsinks, as the Raspi 3B Plus CPU is a lot taller due to the added metal case on the CPU.

Be careful to keep the contact surface of the filed down heatsink as level as possible so the area of contact with the CPU is maximized to increase heat transfer.

Also buy some thermal paste stickers(a lot less messier than actual thermal paste if you need to open the case) to place between the heatsinks and CPU/GPU.

I used this with my RPi3, which dropped the temps streaming 1080p from 85C to 45C.

The Biqu case is similar, I have one and the passive cooling is similar to the flirc's: https://www.amazon.com/BIQU-Aluminum-Raspberry-Case-Enclosure/dp/B01H8L4EM8