What receiver would be best for my epos els3

Hey guys- I'm hoping you could recommend a stereo receiver/tuner to bring out the best in my epos els3. I currently have a yamaha rx-397, and it just doesn't do it for me (it was a gift). What should I be considering in a receiver for these speakers? I'd like it to be around $500 or lower, but could be persuaded to go up a little higher. It needs to have a phono input, and a sub out would be nice. Thoughts?
Thanks much!