I’m a fan of using a quality stereo pre too and frequently advocate pairing a good stereo pre with a cheaper AVR to handle processing. But in your situation you’re looking for better quality processing and balanced outputs, so you’re gonna have to pay up on the processing side, and adding a good stereo pre on top of that would get very expensive. I think a good prepro is your best bet, and if you get the itch down the road you can try plugging in a good stereo preamp to see what improvements may be had.
As as far as prepros, along with the AVM60 there’s the Marantz 7705. If you want more neutral and detailed sound go with the Anthem and if you want warmer sound and are willing to sacrifice some detail choose the Marantz. IMO the processing advantage goes to the Anthem, but as you run 2.2 I’m not sure how much of a difference this will make. Best of luck.
As as far as prepros, along with the AVM60 there’s the Marantz 7705. If you want more neutral and detailed sound go with the Anthem and if you want warmer sound and are willing to sacrifice some detail choose the Marantz. IMO the processing advantage goes to the Anthem, but as you run 2.2 I’m not sure how much of a difference this will make. Best of luck.