Drivetrain questions

[AxeMan]

Ok, here's my situation. I just bought an 89 GT with 112k on it. The car obviously didnt have a very easy life and I want to start rebuilding it to make it a bit more dependable. I just had a little problem with it where the connecting pin in the tranny came out and I lost my gears. I hate having to call a tow truck!

Here's what I'm wondering..
The engine runs strong and I could probably get a few thousand more miles out of it. What's the average price for a rebuild? When I do get it rebuilt I'll probably put in some forged pistons, rods, etc...

The tranny seems like it's ready to start giving me problems. I have a nasty vibration when accellerating. I checked the driveshaft and the u-joints have just been replaced. I was looking into the "world class" t-5's. I've seen prices from 600 used to 1100 new. Would I be better off having the stock tranny rebuilt with better parts or should I just swap it out all together?

I plan on building the car up quite a bit. It's going to take some time though. I want to start with a good drivetrain and work up from there.

Also, if anyone lives in Northeast Pa and feels like doing some wrenchin' on the weekends, drop me a line. Thanks!