Off the top, I like the 40x amp (2 of them)... I had a similar setup with some Rockford Fosgates in my last car. (That is a pair of small 4 channel amps).

Since they are bridgeable, you could use one amp to power the sub and rear speakers (2 channels bridged into the sub, and the other two channels used one for each rear speaker), the other to power the fronts (each gets a bridged signal). The built-in crossovers should be fine (they normally are, I don't know specifically about these).

Overall you'd get plenty of volume but nothing earth-shattering. The setup is easy - empeg - amps - speakers, and that's it. The two amps being the same size lets you easily make some sort of symetrical installation with them in the trunk or under the seats.

There may be something better, but this would be easy, and sound with good speakers. If you're focused on this brand, do they offer anything with a 5 or 6 channel output? It would be a similar setup but likely cost less to get it into one chassis.