I agree with Twisty re price, and I would only go a reconditioned one.... not sure what the difference between the GU and GQ torque convertor is but the cost for my GQ reco TC was just under $400 exchange.
If your gearbox hasn't been sent anywhere yet I would be taking it to Wholesale Automatic Transmissions in VIC, they were a big help when I had to rebuild my GQ Auto box and they seem to know there stuff
Cheers
Todd