Hi there Andy,
As far as me and my colleagues are aware, Nobody actually produces an uprated head gasket for the 1.8T 20v Engines. I've had a look into what our APR Stage 3 cars use, and they all seem to use the Genuine VW head gaskets without any troubles at all.
As for the dog bone mount rubbers, we sell them for £21 + carriage + VAT
and the engine mount above the gearbox, we do a Vibra Technics replacement, which costs £149.95 + carriage + VAT
Feel free to give us a buzz if you've got any more questions.
Cheers, Al.