I'd buy the 7500 amp if budget allows. You'd be more future proof with the balanced inputs, and additional power.

I have the Anthem AVM-50 paired with a 7500, and I'm extremely happy with it. I replaced the 990 with the Anthem.

I was also extremely pleased with the 990. I went with the AVM-50 to get HDMI and the video upscaling/processing capabilities.

The sound difference I hear between the Anthem and the 990 isn't as great as the sound difference was when I upgraded from a Pioneer Elite receiver to the 990. You can't go wrong with either the Anthem or the 990.

All that said, I agree with previous posters about focusing on your speakers. In my opinion, a budget receiver with great speakers will sound better than a great receiver and budget speakers.