As you know i have 4 new kicker 4x6 at 4 ohms and i have a 35wx2 at 4 ohm amp and 50wx2 at 2 ohm. its a 2ch amp and i guess im asking would it be better to let the headunit power 2 outta the 4 rear speakers and let the 2ch amp do the othere two, Or should i take all 4 speakers and run them together to creat 2 ohms??? so they all get 25watts each btw 25w is there rms and 50w is peak on each speaker. and the headunit is 50w x 4 but i dont think it would really put out more than the kicker amp would

 

The headunit is 50w x 4 peak, not rms. More likely 15-18wrms. The speakers output would be balanced if you run all four off of the amp, but the amp will run hotter. As long as it can breathe where it's mounted, I don't see a problem there.

 

I would run them all off the amp and present a 2 ohm load to the amp.
Check this out for more info on amp/speaker wiring:
http://www.diyaudioandvideo.com/FAQ/Wiring/