Always happy to help!
Oh, I almost forgot - tires are KEY.
Go to your club and ask around - run whatever everybody else is running, no questions asked. If your club is a hobby shop, they will definitely stock whatever the people like to run, since tires are consumables with these cars. I just...
First things first: do what @bill_delong recommends! Have somebody else put a few laps into your car.
But I'd definitely run the kit setup for a few track days. I'm about a month ahead of you with my B6.4, also running 21.5, and that's what I've done. The kit setup isn't perfect, but it's a...