If you truly need a receiver, the Outlaw RR2160 is pretty much the only game in town.
If you can get by with an integrated amp with multiple outputs, then there are more possibilities.
My advice: use that $600 to improve *one* of your components (either receiver OR speakers), and the start saving up again. No point in dribbling it away with $300 each. You should probably be looking at ELAC speakers.