Heres my advice for a setup, I challenge and enocurage anyone to recommend a better setup for the money
Id stick with the 7140 for a source unit.
Id runa Memphis Mini Belle for amplification. It does a good amount more than rated power and it looks sexy. GO TO YOUR LOCAL DEALER FOR IT!! I bought one for an install and paid 400 out the door plus its the only way memphis honors their warranty.
16-MC5.700 - Memphis 55 x 4 / 500 x 1 Hybrid Class D Amplifier
Next Id run pioneers TS-C720prs. The midbass is phenominal and the tweeter is smooth. Look around on Car audio forums, nothing but great reviews. The T/S parameters measure better than sets that cost 3 times as much. There is no better set for that price.
TS-C720PRS - Pioneer Premier 6.75" Component Speaker System
Id Run a single 12" Image Dynamics IDQv3. The sub is very comparable to a 12w6 in output and sound quality and a dual 2 ohm will get teh most out of the amp.
IDQ12V3.D2 - Image Dynamics 12" IDQ Version 3 Dual 2 Ohm Subwoofer
For wiring Id go with an all in one kit from soundquest( its actually stinger), it has all the wiring you'll need. you just need to grab an extra set of rca's.
4 Ga Gauge Amp Amplifier Wiring Kit+RCA SQ by Stinger - eBay (item 130325226377 end time Oct-15-09 08:41:47 PDT)