How many Amps for 6 speakers??

I'm in the process of completely redoing my sound system but need a little advice. I am replacing the 4 factory Clarion speakers with Polk Momo MMC 650's and adding 2 more in cans on the tower. The Clarion head unit should be fine but I know I'll need much more power to make these speakers really sound good. I already have an Infinity Baselink Powered Sub so really all I want to do is power the 6 remaining speakers.

Any suggestions on amps and the set-up for 6 speakers? Should I get a 6 channel amp for all, a 4 channel and a 2 channel or, 2-4's and run the two tower speakers off one?

I'm not an audio guru so some possible suggetions with wattage would be much appreciated!