amplifier question

[wookie909]

okay, quick question here. I have an Alpine MRP-F240 from my old Ranger that I'm thinking of putting in my RF equipped KC. The specs on the amp can be found here:
c rutchfield.com/S-aeTe6qKfvlI/App/Product/Item/Main.aspx?i=500MRPF240

Right now the truck has JBL GTO 6x9s swapped in place of the factory door speakers (they sound great by the way) and I eliminated the underseat vibrator and put in a powered Kenwood 10" sub behind the driver's seat. It sounds awesome and all that, but it is just too big. So what I would like to do, if possible, is run the front speakers off the front channels (2 ohm load) and bridge the rear channels to power a sub in a smaller enclosure (preferably an underseat enclosure). Will this prematurely fry my amp? As for which sub, I'm thinking maybe a 10" single coil 4 ohm, or should I go with dual coil?

Suggestions? Input?

Thanks!