Preamp advice

I agree with Glenn N. the McIntosh is a wise choice with a the LaScala. I'm sure you will be happy with that choice.

This thread might be helpful on matching preamp and amps.

I'm also trying to sort this out.   If you have amps with an input sensitivity of 2.15 Vrms, and a preamp with maximum output of 22 Vrms, would this not be a good match because you can only take use the first 2.15 Vrns from the preamp, and this would reduce your signal to noise ratio?    So in this case, a low gain preamp would be a better mach to this 2.15 Vrms amp?

Just a comment from my experience. I have never considered anything but sound quality in choosing preamps and amps in the over fifty years I have pursued high end audio. In that time and more than a dozen preamps and more than a dozen amps never had an electrical mismatch of any kind.