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!!!
I think you are out of luck! I have never seen a preamp do what you are looking for! To do what you want you would have to put external attenuaters on the speakers or amps to control volume. Good luck!
2x Adcom GTP400 will keep you in your $300 budget or bellow. Search ebay or CL. Hope this solution helps.
2 Adcoms is a good idea, but GTP400 also contains a tuner.
GFP-565 costs a little more and is a decent budget preamp...
I have an NAD C162 preamp. It has two sets of outs on it. One set of outs has a level adjustment on it, which could serve the purpose that you're chasing, although the know is on the back of the unit.