Reddit mentions of KnuKonceptz Kno Knoise Kolossus Sound Deadener 100Mil Thick 35sq ft Car Kit

I've got the Kollosus sound deadener

http://www.amazon.com/KnuKonceptz-Knoise-Kolossus-Deadener-100Mil/dp/B009KXF9MW

http://www.amazon.com/Rockford-Fosgate-R250X1-1-Channel-Amplifier/dp/B00BF6HX8U/ref=sr_1_1?ie=UTF8&qid=1462994649&sr=8-1&keywords=rockford+r250

This amp

That sib in the enclosure should work, but double check your behind the seats measurements.

http://www.amazon.com/KnuKonceptz-KCA-Complete-Gauge-Installation/dp/B0050I6KII

This wiring kit should work, you might have to trim it a bit and/or cut the length slightly to fit in your truck, but all that means is you can use ask that extra wire to do a big three! Menards sells some dope ass 8/6/4/2/0 terminals, they're silver and like five bucks for 2 but they are amazing. You can crimp them on with a bolt cutter (be gentle) and back fill with solder (electrical, not plumbing) to make secure connections. It's copper clad aluminum, so it poetically won't work well to upgrade to, say, 1000 watts, but for 300/500 it'll work.

Head unit is good.

I'm sure you did the research on the harness, but did you get a dash kit? You'll probably find it around the place you got the harness.

Same thing with door spekkers. Disconnect the rear pair though, you'll have better staging just using the front anyhow. In the future, you may wish to amp them, but for now they should be okay. Skip the kick panels, your probably not going to care much about the extra noise.

http://www.amazon.com/KnuKonceptz-Knoise-Kolossus-Deadener-100Mil/dp/B009KXF9MW

This sound deadener could make up for any missing volume I'm sure, but you probably won't need 30 sq ft, you might try they're 14 sq ft door kit. Make sure you clean the surfaces with alcohol and lint free towels first before applying it.

You could just skip that last one though, probably not worth it. .. but the Option is there.

So, in conclusion, measure, double check, triple check, then order.