Heya Onebullet,
That's a very ambitious plan but if you can pull it off, my hats to ya
I like the idea of getting a used ATV to putt along with even if it's 2 wheel drive. Alot of people turn those in for newer models.
Ican had a very good suggestion. I would think it would have to be a national non-profit. 50 states - 50 ATVs. Perhaps go and signup for useage? I would suggest a name like DisabledtoField! or some such.
Anyhow, perhaps a permanent HC sticker could be put on them.