Thoughts, in random order.
Ken, I have the AMC bellhousing pattern blueprinted in several ways. I also have the Ford smallblock pattern, the Chevy smallblock pattern, and the Ford 3.0 Vulcan, not that that's all that important. Motor mounts are a different story but I can give you my info on bellhousing/crank adaptation if you need it.
12Vguy stuff is nice but I'm never gonna use it. My harness is gonna be significantly more complicated than yours as I'll be running 6 injector wires and 6 coil wires in addition to all the engine control stuff, and at that point it's probably worth it to me to just buy the DYIAutoTune harness and cut it to length. I'd suggest the same for your application. The wires come preconnected to the plug, color coded, and labeled as to what they do. If I did it myself I have two options...I'd either scavenge multicolored wires out of the various harnesses I've accumulated, and build the D-sub connector myself, and be stuck with troubleshooting it if anything goes wrong. But having uniquely colored wires connected to the proper plug and labeled "INJ1" "INJ2" "IAC" "TPS" etc and matched to the MS pinout seems really appealing to me right now.
I have part numbers for all the switches and stuff I used wiring my remote winch panel from McMaster, it's easy and pretty economical.
I'm gonna use wire loom anyway...what's your alternative, ribbon cable or a rat's nest?