This topic came in just at the right time... or not.
Currently I'm having llotsa problem with my gearbox too. The gears got stuck mostly at 1st and 2nd and wouldn't disengage. Caused me lots of problem while driving. I just hope it wasn't a kaput case otherwise it's down to money again:(
I've seen a couple of gearboxes for GTi during my random search on google, one was RM1900.00 dammit. But that was a good three weeks or so ago...
Good luck searching bro, be patient:)