Depending on your price range, For components, Infinity makes a decent set 6010cs ($120), as well as a decent set of 6 1/2s in the 6012i's($66)
Focal makes great components but they are pretty pricey. if you can find the 165A's, nice bang for the buck.
CDT makes great components and 6 1/2's. Look into the KA-61's($99) , EF-61NEO's ($189) , EF-61FG ($199). and their 6 1/2's CL-6EX ($99)
But if you want to go a little off mainstream, Elemental Designs (website
www.edesignaudio.com look into their Components eDi 6000s. about 145 per set. With these, you can mount the tweeter in the speaker, so, put the tweeter for fronts up in dash location and midrange in the door, and then mount the tweeter in the midrange for the back doors.
I would forget about the Dash speakers (if you actually have them) cause you will run into impedance issues if you try to run three sets of speakers off any headunit.
For Amps, look into Elemental designs nine.4x, kicker zx350.4, diamond audio 4 channels, or even the infinity 7541a is a steal for the price.
Stay away from Sony, Pioneer, Lanzar, Legacy, Sundstorm, Jensen, Audiobahn, and others.
All of these speakers except for the elemental designs can be found at
www.woofersetc.com.