[FarmerShawn]

Great hints on using whey - I'm going to try that this year.
As for varieties, I am definitely no sauerkraut expert, having only made it for the first time last fall, but I used a red cabbage variety for one of my batches, and the resulting dark pink color is really striking, and the flavor was way better than the green cabbage batch I made. I can't really say what variety of red cabbage it was, because I grew three different red ones, and didn't keep track of which was which at harvest.