Ok im thinking of getting the PIONEER TS-D6802R for my truck, and I don't really know much about audio so can someone describe what kind of amp I would need to power them.
Here the speaker page:

http://www.pioneerelectronics.com/PU...neer/TS-D6802R

 

I'd recommend getting the 6 3/4" component version (you should be able to find them for $125 or so online) which comes with 6x8 adapters. Pioneer TS-D1720C or Pioneer Premier TS-D720C (same price).

I've got the Premiers running on 100W RMS each in my front doors.

 

You will not need an Amp, unless you want more volume...

You can install them and then see if you want more... why do you want new speakers.. The stock speakers cant take too much power.

If you want more volume then you will need an Amp also.. but then you should replace all 4 speakers.

For an amp you would want a high input amp. I have a Kenwood.

This makes my truck boom. I have Polk Audio speakers and a Sony Expode 12" sub.