good clean power, lots of it. Not for the purpose of cranking, for the purpose of just sounding good.
that's what i recommend. I don't think with 3 grand you should spend more then 400 or 500 on a deck. I rather have it sounding good then inviting you when you walk in your car or watch movies. My system is all about audio, nothing that comes out all fancy like all that cheesy stuff young guys do to show off.
I have kenwood, alpine, mbquart, and jl audio gear.
MB Quart is a great speaker, but might sound bright to alot of people's tastes. With electric guitar it could be a painful experience, but if you setup your crossover on the deck pretty well it won't be a problem. They offer amazing midbass, and snappy highs that will sound excellent if tuned properly.
I have a 4 channel kenwood excelon deck bridges to 150 x2 for mb quart refernce premium components up front.
For the rear doors i have a 2 channel alpine v12 powering mb quart discus 6.5 coaxial speakers.
I just got the new alpine v12 1000 class D amp powers dual JL audio w3's in a fitted encloseure, just mounted the amps on the back, nothing for show at all.
I use all stinger interconnects, i forget the make of the cabling, but i use 12 guage for the woofers, and 14 for the speakers, i have a cap, stock alternator (my car came with a good one) and, a battery upgrade might be an option later on. This is good for sound.
Basiclly, I have my system tuned for rock music, i listen to primarily classic rock in the car, and alot of industrial electronic stuff, both sound good.
hope that helps, i also believe getting things installed properly is key, or atleast do it along with a guy that has wired a few systems before. Don't let some fool pull a hack job on your car... and be warned most of the time these shops do crappy work and unless you have a good relationship with them, they will try and take you for a ride as far as price. I think he should spend the 3 grand on the gear itself, then maybe get another 300-400 to spend on getting things installed. That might sound alot, but its worth it