Suggestions for a three channel amp

I'm thinking of upgrading my two NAD 218thx's for a three channel amplifier. (I use the fourth channel for rear center surround) Current system uses a Rotel 1066 preamp with standard Shearwater speakers. Source is the new Sony DVP 999es. I was thinking of the Aragon 8008, but I'm not sure if it will make a difference. What price point do you think I would have to reach in order for me to really hear a difference.
Thanks