Any ideas? I'm thinking about buying this car, but I dont know whats wrong with the transmission or what I would need to do to fix it. Any and all help appreciated. Thanks!

http://redding.craigslist.org/cto/1602759837.html

 

Sounds like it has multiple issues:
".motor runs decent needs little carboration work" - Seems like if it were this simple he would fix it and ask for more money.
" tranny skips second gear ..." - Again, seems like if one of the other trannys would fix the issue, he would install one and ask for more money.
Call me cynical, but it really sounds like a project car.
You could probably install each of the other trannys to see if they are good, but it sounds like a rebuild is in order. This could be a good time to get a performance build and a stall.
AFA the engine, you'd probably want to start with the basics; compression test, leakdown test, possible carb rejetting, possible tune up.