First of all, there are a good deal of special tools involved in rebuilding almost any ATX. If he has everything he needs, then that should not be a problem.
As far as where to get a rebuild kit? There are tons of places that carry a rebuild kit for our cars. I know that wrenchhead.com carries a few different kits, so you could start there. One thing though... You would really need to upgrade the pistons in the valve body (I would suggest pistons by Sonnax) and there have been a few improvements in the pump seals, the coast forward clutch, just to name a few. If you get a simple rebuild kit that includes maybe new bands, some of the clutchs and seals, it will not really accomplish much since you have a '95 other then getting the car ready to be sold I guess. There are way too many updates to that year model to really justify a full rebuild, IMHO. That is why I feel it to be wiser to just by a remain with a warrenty and install it yourself or have a shop do it. Most might only charge anywhere from $200 to $400 dollars labor.
As for your stated problem. That could be something as simple as a Vehicle Speed Sensor (VSS). I have read several posts throughout the boards that have had the same problem and it was related with this sensor. It is located behind the instrument cluster. To get more information on this topic, you could try searching in this forum and the troubleshooting forum using the words "VSS" or "Vehicle Speed Sensor"
