Picking the right amp...

I am looking to get a new amp. Preferably a 5 channel to drive my N802's and Nautilus HTM1. 5 Channels so I can bi-amp my N802's and the remainder to drive my center. My system is 80% home theater, 20% music. Although when I listen to music, I want to to be amazing.

My processor is a Yamaha VX1 (will upgrade that but down the road). Currently I have a B&K 4420ex (I believe it is 200x2). I don't have balanced outputs but would like to have them on my amp so that when I am ready for the future.

Here is what I am looking at. Any opinions on these, please share.

New Earthquake Cinenova (300x5)
BStock/Used Sunfire Cinema Grand Signature (425x5)
Used - Krell KAV-1500 (300x5)

My budget is $2500 (I know I won't find the krell at that price point, but if poeple tell me I need to spend the extra money....I just might.

Also, should I be looking at getting 2 three channel amps and bi-amping everything? What works best with the N802?