I have a 1998 Chevy Tracker 4-door 5-speed manual.

The tranny has noise in 3-rd and 5-th gear. I suspect bearings are starting to fail.

I see on eBay Rebuild Kits for 5spd Transmissions. My questions are:

1. Is it worth it - are those kits any good?
2. How difficult is it to do a tranny rebuild. Can a weekend mechanic like me do it?
3. Are the manual transmissions the same on 2-door and 4-door and throughout the years - maybe I should better buy a used transmission?
4. Where can I find a good used transmission in the Lower Mainland?

  The kits are well worth the money,and the rebuild is pretty easy and straight forward.I have done several manual rebuilds on several different type of vehicles and the results are allways worth the investment.
  It is not very difficult,and a chiltons manual will go a long way.A rebuild manual is even better,and i got mine at auto zone for 15.00 dollars.Even without the paperwork it is not to bad.

Can you elaborate a little more what is involved in this process.... Does it require any special tools?

   Snap ring pliars,rubber hammer,and bushing/seal drivers are the only tools besides regular old wrench,wratchet /socket type stuff.
  If you dont have a seal/bearing driver kit,Autozone rents them,you but it for 50 bucks,return it when your done,and get a full refund.Don't go cheap on snap ring pliers.NAPA has some for about $25 that are awesome,and have a beefy handle you twist to apply pressure,no having to squeeze the snaprings in and out by hand.They work on inside and outside rings and rock!!
  Other than that,it is common tools,and a few gears,shaft,etc on the inside of the tranny.