Seriously, I have a NAD C-160 preamp and it sounds very nice. NAD makes good equipment and I think you would be very happy with it.

But I also think that once your wife sees the warm glow of a tube amp, that will be the part of the system she likes best. Attractive tube amps have a presence in the room sort of like a fireplace, an almost romantic appeal. What gets you in trouble are the erector set looking amps, those don't generally get the same reaction as a good looking tube amp. But when the chassis is attractive, the warm glow of the tubes make the amp look like art with soft lighting.