I'm at that point right now too!
Here is my thinking-
My first steps are:
1- Track down all info on compatible (direct swap in or limited modification) transaxle's gear ratios and final drive ratios first. R&R the complete trans if one has the desired ratio.
if this is not acceptable...go to the next step
2- Track down all compatible trans gears or final drive differentials that can be swapped into the trans from 'related' transaxles.
if this is not acceptable...go to the next step
3- Research some racing or machine shops that could 'make' a gear set for you (I was quoted about $700-800 for this when I called around).
if this is not acceptable...go to the next step
4- Pull out hair and scream loudly.
if this is not acceptable...go to the next step
5- Run large diameter tires and keep your speed down.
if this is not acceptable...go to the next step
6- Join EcoModder and search for answers in previous threads.
if this is not acceptable...go to the next step
7- Post New thread titled 'Regearing a tranny' and hope someone has some experience with this sort of thing!