Hmmm I had another idea. I used to dabble around in producing techno music quite a bit. I mostly used a program called propellerheads reason. Its an amazingly fun program to work with, extremely visual, sounds great, and can be had for free at the usual places.
I don't see any reason why you couldnt use it in real-time, I dont recall it using that much CPU unless you had a zillion devices going.
It basically gives you a big virtual pro-audio producing rack, which starts as an audio output device, where you basically have a reproduction of your soundcard. You can flip the rack around to wire it up however you like.
for example you can take a stereo source, and use the 'splitter' device to split it into 4 or 5 signals. you can run each signal to its own EQ, and filter it in every way imaginable. You can run them through individual delay devices, or other effects devices. then you can run each output to individual channels on your soundcard.
i would imagine that by using this software or Cubase, or Logic, which are both even more professional (but less intuitive) competitors, you could get just the result we're looking for.