For under $600 the Yamaha RX-V667 packs the latest features including HDMI1.4. If you don't need 3D then you could look for deals for the Denon AVR-3310 or even the older Marantz SR8002.
As for video processor, many people think they must have ABT or REON. To me it is mostly hype and hearsay that gets spread around and exaggerated in the process. The fact is that it matters little unless you enjoy watching synthetic test materials or you watch DVDs on huge (>60") screens. Even then I believe the difference between those top notice VPs in AVR and those in a good BDP and/or flat panels are not that noticeable and it is the quality of the transfer that has the most impact on the upscaled PQ.
That being said, if VP is important to you then go for the 3310, assuming you can do without HDMI 1.4/3D.