full suspension would be a poor choice. you could go with a hardtail (front suspension)... not ideal but doable. better if the fork can be locked out. better still if you swapped out the sus fork for a rigid one:
Nashbar Rigid 26" Mountain Bike Fork
Nashbar Chromoly 29" Mountain Fork

best would be an old, rigid bike:
https://atlanta.craigslist.org/atl/bik/5900517361.html
https://atlanta.craigslist.org/nat/bik/5936383748.html