If you're using an Oppo, and not using a turntable or radio tuner, I suggest skipping the receiver and just getting a 3 or 5 channel amp. Get a 5 channel if you plan to upgrade later.
The Oppo does very well directly into an amplifier, and the surround settngs can be controlled from the Oppo.
The Oppo does very well directly into an amplifier, and the surround settngs can be controlled from the Oppo.