Take a look at these quick (and crappy) snapshots. There's just no room for that kind of wire management. On top of that (and as I'm sure you are aware), the front of the amps house the gain controls, so they have to remain accessible.
I have not determined if the noise is coming from all or some of the channels. That's the next step in the troubleshooting.
Here's what I'm working with. It's really the only logical layout that I could determine. given the space constraints. It doesn't seem this messy in person, I'm actually a little embarrassed at these shots, but here's where I'm at.