Looking for pre with 2 volume controls.

Ralph Karsten puts channel trim controls in his Atma-Sphere pre-amps, with a master volume knob as well. I think they will allow you to do what you want.

Some of the older Canary Preamps have dual volume controls.

Canary CA 980

Good Listening

Peter

Jadis JP80 and 200, and JPS2. Very expensive, though. As Al mentioned, you could accomplish the same thing with a balance control (which is becoming less and less common these days, it seems).

I'm also curious about the two different mono amps.

Thanks Rcprince, finally, someone else questions the use of 2 different mono amps.

"I have 2 different mono amps..."
Perhaps you should consider getting matching amplification for each channel instead?