Generations/revisions?

Hi every one, I'm in the process buying a second generation Mr2 Turbo. But before I do, I need to know somethings.
Whats the difference between the 93 turbo Mr2 and the 91-92 turbo Mr2?
Correct me if I'm wrong, but didn't the 93's come with a stock LSD and a stiffer suspension?
Whats the difference between all the revisions of the Mr2 and what are all the generations?
I know I already asked this before, but I still don't know where all those speakers are.

Thanks