I'm new to the forum, and just getting back into cycling. I need an enjoyable fitness program, and have decided to do some trail riding. I have a fitment problem due to a neck injury sustained in a motorcycle accident. My neck is pretty stiff, and looking "up" for very long leaves me in pain. I went to 5 LBS in Houston Saturday, and didn't find many bikes that offer an upright riding position, and exactly none with dual suspension, which is necessary to keep me off pain pills. One shop manager suggested an All-Mountain or Downhill style bike for their geometry. With South Texas being flat, there were no bikes like this to try at any of the LBS. I've located several bikes like the Session 7/77, Specialized S-Works Enduro, and Santa Cruz Bullit on Evil-Bay, but have questions.
I'm 5'6" with a 29" inseam (long torso), and ride with the seat about 25" above crank centerpoint(measured along seatpost). My old rigid bike is 16.5" with about 21.5" top tube length. By swapping bars, stem, etc, I was able to get a comfortable riding position with the grips at about 4" above the saddle. I just can't ride the rigid bike except on the road because of the jarring.
My question is whether an AM or DH bike can be configured in this way, and should I go with a 15.5" or 17" frame? I ride ranch roads and singletrack in flat South Texas, and Hill Country State Park trails, so I don't think component selection is much of an issue, so don't worry about that. I know my situation is not applicable to most people, so any help you guys can offer is appreciated.
Gulf Coast, Texas