Pre pros are generally not necessary. The processing in avrs from reputable brands are plenty good enough. A lot of guys actually use their avr as the Pre if it has preouts. There are plenty of good avrs like the 7s and 8s from onkyo, marantz, pioneer, Denon, etc. also if you get one with audessy then setup and Ewing is a breeze. What speakers are you running and what's their power requirements? If you need 200+ watts then an avr will not suffice. Also, while Emotiva makes GREAT amps for a great price their prepros have had a lot of issue and I'd stay away. Outlaw seems to have a more reliable product, but back to the point again just using an avr as your prepro won't cost any more, likely give you more expand ability, and offer great room correction and eqing like audessy and whatever pioneers new one is called.
Bought from - Hazardous0388 (4 db Drive 2000.1s), Psychoacoustics (4 Powerbass XA 3000'ds), and blackedoutavy (PPI A200)
Sold to - D-Rew (Knu 1/0), d77543020 (Knu 1/0), F1McLarenAGR (Audioque 4x90), and SacTownBully84 (Knu 1/0)
Traded with - SacTownBully84 (my xa3kd for his xa1.5kd + cash)