I want to install 4 new coaxial speakers and 2 new subs into my EL Falcon. What would be the best amp arrangement?

Say for arguements sake a 1200 watt system. Would one 4-channel amp for the coaxials and one 2-channel amp for the subs be ideal?

Cheers!

What sub's? What voice coil configuration?

You could use one 4 channel to run all 4 speakers and a decent monoblock amp to drive the sub's.

Any particular reason why you want to use coaxials all round? I'd highly recommend stepping up to a decent set of component speakers up front and just chuck a pair of coaxials in the rear for fill.