yeh W58 with a custom bell housing would be the best, its a tuff box and its been done before so you will be able to get help from people of you need it, hope your back gets better soon.
I blew up the engine (4a) the other day, Lotsa smoke, engine rattles loudly, runs on 2 cyl.... ha ha ha ha ha
Now time for 13BT....
1974 MX22 MARK II CORONA HARDTOP COUPE - Awaiting a full restoration