Also- I would replace the entire upper timing cover for peace of mind, but as far as I can tell they're not for sale anymore. Anyone know where I can find one? If not, is it safe to use some RTV on the gasket sealing area so this doesn't happen again? Or will that just make things worse?

 

I finally had a chance to dig through the service manual and order parts today. Here's the parts list in case anyone else finds themselves doing this job:
066109091A x2 (this is the gasket that's failed)
021121119A (thermostat to timing cover gasket)
022121119A (timing cover to head gasket)
022103483E (valve cover gasket, probably not necessary but better safe than sorry)
You'll also need RTV and coolant, I bought 2 gallons of concentrate and I'll just do a system flush.

The VW manual says that to install the VVT gaskets I need to use tools VW 3378 and VW 3253/6. At the moment, these cost about $100 if I'm buying both. I didn't use them when installing these gaskets during my timing job, and clearly I should have as both have failed as a result. I'll probably end up buying these tools on ebay unless someone knows somewhere else I could get them, or ideally some cheaper tool which can do the same thing.