I'd much rather stay away from one brand in particular and focus my install and equipment rather on what i'm looking for, what i can get for the best price, and what piece of equipment will suit my needs better than sticking with one company just to it looks ok.
If you want matching amps, go that route, as far as for drivers, processors, and HU's, mixing and mathcing is the way to go. One company can excel at making amps, while another excels at midranges, or midbasses, and another at Subs.......
For a really nice setup, and if you have the ability to go active, check out the LPG 25/26 for tweets, and the Seas CA18/G18, and be done with your front stage for just under 200 for the drivers. Another few hundred for amps to run them suffeciently, a good 40rmsx2 on your tweets and another 80rmsx2 on your mids, and pick up a nice sub, and you would be astonished at the clarity and detail this combo can do.
Stay away from caps...waist of money.
Really look into the DIY market away from mainstream companies....i can't advise that more than anything.....you will save money and reap so much more benifits than sticking with mainstream stuff. Mabey its just me though.