Since you do have time on your hands, the idea about the Denver bicycle co-op, should be fully exploited. I would suggest that you locate a mtb frame and begin to build your own mtb. You can then modify it to suit your own physical needs.
Some bicycle companies make steel frames. Frames that are strong enough to take the heaviest of loads.
Here's a couple of steel frame sources, should you decide to go that route:
www.nashbar.com/bikes/Product_10053_10052_546016_-1__202388
The Breezer MTB Frame
http://store.somafab.com/mtbframes.html
SOMA- MTB Frames