Trying to find the right TYPE of preamp...

OK, so here's my quandry: I have 4 Carver M400 "Cubes", one to power each of my four stereo speakers: One pair of Carver Amazing Silver MK1V's, one pair of Infinity WTLC's. I want to be able to run '4-speaker stereo', with the ability to fade the back channel/lower its volume should I wish, rather than have all 4 at the same volume all the time.

The only pre's I can think of that both fit in the esthetic and sound qualities of my system (incl. all the other components in it - no tuner, though, but that's another story) is either the ole Phase Linear PL4000 MK1 (with the joystick in the center of the faceplate for front/rear-left/right control) or the Carver PSC-50, which simply seems to use balance and fade controls.

The conundrum is this: What else is out there that would fit the 'design style' of the gray-ish Carver pieces (gray, silver or black) and give me the control I want? True, I'd rather have Phase/Carver gear, but SAE and DBX are brands I like and use as well, so they're definitely worth a look.

I DO, however, want to keep the cost in the $300 range, if not even to be able to barter some of my audio gear for the pre and other gear I'm wanting (e.g. Carver/SAE/old Marantz tuner, turntable click-pop filter, DBX 3BX).

Thanks in advance!!!