Bi-Amping with Sunfire Theater Grand IV

I'm looking at BI-Amping my NHT Classic 4's. My processor is a Sunfire Theater Grand IV, balanced out to an Emotiva 5 channel amp. I'd like some different scenarios as to the best way to bi-amp. Would using something like a NHT SA3? Another Emotiva, using 4 of the 5 channels to drive the Classic 4's the 5th to drive the center...then the new amp for the sides and rears? The Sunfire has Balanced and unbalanced outs...3 subwoofer outs of which I'm using two for my two subs...any help would be great

Mike