A little off topic but how did you like the audio setup you did?
Well, as usual, it's hard for me to give a short answer!
I pieced my kit together using components I already had stored away, and didn't buy anything except a little wiring. That being said, the "new" amp I used had been sitting for 7 years, and only 2 of the 4 channels are working... or it could be the crossovers that have a problem. I have had so much else going on that I really haven't had time to diagnose it.
At any rate, here's some quick guidelines. Keep the speaker placement in the doors low... did I have pics of where I put the tweeters in the kick panels? It's natural to want to put speakers high where you can hear them, but this results in poor sound quality, a high noise floor, and grates on your ears.
Putting 6. 5" components in the door seems good for highs and mids. If I was starting fresh, I think I'd put a single JL Audio 12W6 sub in a 1. 25 ft3 custom enclosure out of 3/4" or 1" MDF. You could put this together for ~ $300 or so doing craigslist or ebay, and have bass that would rival a setup costing 10x as much.
I've come to love USB/SD card capability in the headset. I don't know if it's just me, but I've had terrible luck with the longevity of rotary knobs for controls. They seem to go bad after a year or two... especially if your truck ever sees dusty conditions.
Good audio work is time consuming. Do it yourself, and use the extra money to spring for higher (not highest) end components. For the door speakers, Focals are good. I'm running Infinity perfects, and they're pretty good. I think the 12W6 sub is the best for the buck by far. I don't have strong opinions on head units or amps for the low/medium end range... except that the Rockford Fosgate I had hit much harder than was rated for.
A small, single cab truck is a little difficult to get good surround spacious sound out of. If you could score an old KDS-P110 equalizer, I think it'd be the best money spent if you're wanting surround sound.
I used some 4x10 speaker brackets from an '80s model dodge for the rear cab corners.
I know I've rambled, but maybe some of it helps. Ask any specific questions if you want and I'll try to answer!
--Eric