nice, I have a vert too, but my seats were NOWHERE near as nice condition, and my car is a 91, lol.
Have you considered using a Miata Torsen diff? I know that they drop right into an N/A diff housing, and work quite well for low HP cars. I want one myself, but dont know if I should rather save up, and get the FD torsen +turbo housing and trans...
actually, come to think of it, that would be a killer setup, turbo trans, new preformance clutch, and FD torsen diff, unless you go nuts, this seems like a pretty solid drivetrain!
(plus you can get the Banzai poly engine and trans mounts in the process, since yours are probably not in that great a shape, worthy investment btw!)