Yep. Get a wreck/write off from auction. I just bought a 2001 Audi S3 wreck for $4900 (minus interior)!! Only has 47,000 k's. I'll be taking the 20vT outta that and dumping it in my Mk2. As this motor already has 220bhp (which i'm quite happy with) i wont have to faff about spending $$$ modifying a "normal" 150bhp 1.8T
This way you can also take all the extra bits you want for the conversion and sell off the rest of the wreck to make some money back. You could possibly break even if you play your cards right with some luck! (obviously depending on what ya buy).
Personally, i've read that the VR6 lump can be a bit of a bitch to work with and it also is a heavy engine. To modify it, you will need to spend a lot of time and $$ tuning it just right to make sure it wont need to be rebuilt every two months. On the other hand, the 1.8T is very strong, relatively light, and capable of massive power increases without lunching itself.
BTW: Keep those small bumpers dude! Too many big goofys around