My husband suffered a spinal cord injury a few years ago, and needed to use a walker for a while. (He's much better, now, and only needs a cane.)

We flew on AA twice while he was still in the walker. They could not have been more accomodating and were super-nice about it. We were allowed to board before anyone else, even FC and Exe Plats, so they could get his walker into the closet at the front of the plane.

My suggestion to you would be to call each airline and explain your situation. Bulkhead seats would probably be best for you, but be aware you have no underseat storage. All carryone items, including purses, have to be stowed in an overhead bin. Get to your seat and immediately stow your stuff before the bins run out of room.