I know someone who went to the B&W factory and they had Levinson amps plugged into the N800s for what it's worth. I know Electrocompaniet makes some nice high-current designs and even named their Nemo amp to coincide with the Nautilus line, so that may be worth a look too. I recently got a Marsh A400s to demo and to say the least I am extremely impressed, and it is a screaming bargain at around $2k. Best of luck.
Tim
Tim