Another idea, stitch the GDMBR to the CTR at around Breckenridge, and the CTR to the AZT at Durango and...? (Utah, somewhere - there's gotta be something - a BIG something - well, here's something -> http://www.bigdogadventures.com/Moab.htm
Moto routes scare me, just because the amount of beta between resupplies is a little questionable at 9mph and 6,000 calories a day.
I think doing the CTD w/whatever you want would be a thrill. Since it's not all complete, you could simply have Lat/Long points that you're required to hit, no matter the route. Thought the big ditch was hard? Ha!