if you're up for a trike, sun makes a heavy duty trike, it says the max height is 6'3" though, so it may feel a little cramped, i'd email the shop here:
http://www.bicycleman.com/recumbents...bent-trike.htm
this looks like a really comfortable bike (not speedy, but veeery comfy) and it runs at around $1300 i believe, it's HEAVY (65 lbs) but . . . it's steel, and probably has the strength you'll need
i'm sure the guy that owns this site will have something for you, i've read about a lot of the bikes he sells, and he seems to have first hand experience with all of them : ) good luck on your search!