So your using the tranny from the 1.8T?
Im not 100% sure on the size of the clutch assembley from the 1.8T but im pretty sure, since its a 5 speed, its 228mm, im sure someone will know for sure.
All VR6 clutches are 228mm (MK3 at least) also so any one of those would work fine. Only thing is, is im not sure if the bolt pattern for the pressure plate to the crank is the same from the VR6's to the 1.9IDI. I do know that the VR6s pressure plates fit on 1.9TDI's though.
In the MK4 generation I think most 5 speed transmision engines have 228mm clutches, besides the 2.0L. They also had the 6 speed transmision which had a 240mm clutch.
Main thing you need to know is if all the engines have the same PP to crank bolt pattern.