Any of the receivers from Onkyo, Yamaha, Denon in the $500 range are good choices. Most folks would pick a receiver that has pre outs so you could add an amp sometime in the future and make sure it handles 4 ohm load.
That said, you are not going do *any better* than RX V659 as suggested by Davemcc so why not just buy one and move on to the next step in your putting together your system.
Nick