I'm looking for a nice system for a friend of mine. He's looking for a nice system for his something that sounds good with good SQ and also gets loud but not too loud. His son has a early 90's Toyota 4 Runner. His budget is $500-600 need subs and amp. I know quite a bit but dont want to steer him wrong and wanna know what you guys would suggest. Oh before I forget 10's and 12 inch subs.