This is only my opinion, but FMR stuff is really not the greatest thing since sliced bread, contrary to Internet lore. It's a glorified guitar pedal that just happens to work for 'other' recording tasks.
The power supply determines available headroom, and even my cheap dbx 266 has a +18VDC supply inside. Sure, you use an 18VAC adaptor, but inside it gets rectified and split up into +18VDC and -18VDC for some dynamic headroom. If you want three RNC's and the three power supplied hanging there, they're still only 9VAC, so at best you'd have half of the available headroom in comparison.
I always go with rack gear that has it's own power supply, save the one dbx that was just such a good deal I couldn't say 'NO!' to it. If you cut corners all over the place, including the power supply, what corners did you cut that I can't see? If the retail price is the final end for you, why am I almost paying $200 for a glorified guitar pedal? Cramming in all the parts like FMR does invites noise. The ART is $300 and adds VU meters, gain reduction LED's, output level LED's, and is using enough size to the PC board that interference and noise should be at a minimum. In fact, the ART advertises they use a toroidal transformer for minimal hum and interference. Plus they also thought it was important enough to add balanced XLR inputs and outputs. The RNC makes me use my cheap Radio Shack high impedance microphone. Or, you can use your better judgment and go with the ART. But it's your call.
You can also collect compressors. I have a handful of rack units, but for guitar I must have over a dozen compressor pedals. It's a disease, but they do all sound subtly different. Try as many as you can, buy some, resell the ones you don't use often enough, and figure out on your own what's best for you.
