Bob, you might be best off if you got an older ShopSmith -- one of the ER models. These *can* be made wheelchair accessible. Coming out just after WW II, disabled vets were accommodated, and I just saw a photo of one that was recently given a different base. I'll look for that picture, but in the meantime, here's another.
On a ShopSmith list, there have been at least three guys mentioned who used the machines with bench modifications for wheel chair access.
A ShopSmith would give you a very decent lathe with a 15" swing -- a large number of SS users use them primarily for the lathe. In fact, that was the big reason I got mine a couple of years ago. But you also have the drill press, table saw, sanding disc, horizontal drill all in one machine. It doesn't take up a lot of room, either. Very versatile machine.