if you want only hard core gaming then i5 is more than enough. and the HD7950/7970 with new beta drivers are ripping apart nvidia benchmarks. also they are highly OCable. want extra juice? go for CF.
hope you are not falling for the 'Physx' gimmick from nvidia. incase you have, go thorugh this thread: Info/Discussion : How to configure a Graphics Card dedicated for Phyx, Baseline and Aux
as for surround, AMD gpus too support them. Eyefinity: AMD Eyefinity Technology
and incase you haev not bought your rig, consider telling the config. the experts here will help you get a better config if possible.