Actually, I'm disappointed that the DCX is controllable through RS232 or RS485 and not midi like the DEQ. Until you mentioned that, I though both were midi controlled. The advantage of midi control is that it's an open standard and there are tons of available midi controllers. I do not want to have to use a computer, with all of their complications, in my listening room. I'm only comfortable using computers as a temporary diagnostic or setup aid. (Also, I use a computer in another room as a music file server, but that's another story.)
Meanwhile, I have been finding some interesting midi controllers that might work, and people would build custom midi controllers who might be persuaded to do this job (could we get a group order?).
Here's one controller that does something close enough for me, a "Dual Footswitch" controller:
http://www.midisolutions.com/proddfs.htm#
With a device like this, you only need to connect it to two switches and you can then send Program Control messages by closing one or the other. I would use this connected to my QSC ABX box, which uses relays to route a signal (or, in this case, simply a voltage) from the input to one of two outputs under remote control. The QSC ABX box has an infrared remote which allows you to select A, B, or X (which is randomly chosen to be either A or B to allow you to perform blind tests).
This would serve both as a remote controller, and it would allow me to perform blind tests as well, to prove I can hear the difference between two DEQ presets.