Well personally I like CLARION head units....The rest is not that good but the headunits are really great.
For the 2 woofers, I have infinity kappa serie. And for the tweeters, and midrange tones, also Infinity kappa serie...
For the amp, I bought an infinity as well....But groundzero has some real nice ones as well...Just don't buy JBL GTO serie. But that is my personal thought
My condensator, is from Groundzero...Buy one when you have a havier amp then 500 watt, otherwise you can't get the watts out of your amp....
You can do also some searching on
http://www.carreview.com/reviewscrx.aspx (was always a great free resource, looks like it's paid and sponsored now, not sure tho)
Andre