I was in the same boat as not knowing what to put in mine...
CDT components up front, CDT coax in the rear and 2 - Infinity 10" subs.
I decided to go with two amps, mono block JL audio 500/1 for the subs and JL audio 450/4 - 4 channel for the fronts and the rears.
Being you are not running rears you could get away with a 4 channel amp and bridge (connect two of the channels together) for your subs and run the other two channels for your fronts, atleast that is how I under stand it but I am far from knowing what I am doing.
Check out this pic of the JL amp and on the left side where the connectors go you will see how to bridge two channels for your subs.
http://www.sonicelectronix.com/pictures.php?id=1868