Sort of a newbie here myself, but I'm going thru a new system build myself and thought I might be able to help on this since I just bought new amps.
As I understand, you're buying the Klipsch RP-280 surround system speakers (5.1) and you're thinking about a new amp to drive them for $700 or less.
If so...I would go with the Outlaw 5000 5ch amp. I think it will more than do the trick for roughly $600.
I have the emo A500 driving 2 prs of Noble Fidelity L85mk2 ceiling speakers...it's great for that purpose, but personally I would want a little more beef pushing my mains.