8 channel volume control?

I am thinking that I could hook my ARC amps up directly to the 5.1 outputs of one of the new DVD, CD, SACD, type players [as long as it includes bass management ]. The only problem I can see is that I would have no control over the overall volume level. Does anyone make a high quality, line level, 8-channel volume pot? [6 would do, but I might as well plan for 7.1]. Am I overlooking any other problem?
check with MSB at www.msbtech.com; I recall it's remote operated. I've never seen a review. I'm not absolutely sure they ever shipped any of them. The price was originally supposed to be $500 but I think the last time I checked it was up a couple hundred.
Not sure if its out of your pricerange, but Jadis makes a 5 channel preamp called the Cinema. It is designed for your specific need but as with all Jadis gear, you can bet it will be expensive.
Thanks to both of you for the information. I was hoping for something cheaper. I can make the box for it myself. Thanks again.