I bought the switches from
OTRATTW. Check their site for pricing on the switches you'd want. I had 3 of them installed in the panel above the parking brake release, and 2 installed in the knee panel below the steering wheel. They're Contura V switches; AEV recommends Contura II and I can see why: the V switches are a bit wider and rub on the framework of the panel. It's a tight fit but all switches work fine, just a bit tight is all. The switch bodies for Contura 2/5 are the same, it's just the rocker that's different.
The switches trigger a relay panel I bought a couple years ago, one of the waterproof Bussman boxes. Here's a link on how to make one yourself if you're so inclined:
http://www.bodenzord.com/archives/473. The switches are rated for 15a or so, but I don't want that much current coming inside the cab so I kept the wiring simpler and only used relay triggers.
As far as wiring, AEV recommends quick disconnects for the switch wiring and I 1000% agree with this. IF you don't put a quick disconnect up at the panel, you'll have to disconnect each switch to remove your dash bezel. I used some two 8-pin EPS computer cable extensions and spliced my switch wiring to that. Here's a cheap cable on Amazon as an example:
https://www.amazon.com/StarTech-com...&qid=1515604467&sr=8-4&keywords=eps+extension
Can go crazy with other colors too if you wanted:
https://www.amazon.com/BitFenix-Alc...qid=1515604467&sr=8-16&keywords=eps+extension
All in all, the process was fairly simple. I just had to extend the wiring from my existing switch locations to the new panel. I spent a couple hours in the house making the new wiring harness, and spent about an hour in the cab running the new harness and making the connections. The physical panel install took all of 5-10 minutes. AEV's instructions are good, but I've also removed my dash bezel a few times doing the RA4 swap and such.