Take a look at ARZ's rear brake kit. It's been a while since I've looked, but he was in the process of making a provision for the rear brake since his big brakes don't have that provision normally. He was going to use a small cable operated caliper from what I remember...
I also think that buckshotglass did the same thing. He bought one of the earlier rear brake kits, and started doing this on his own. That is in his build thread somewhere back in last year, you'll have to dig for the pictures, but they should still be there.
Edit:: Just looked through ARZ's rear brake thread and he figured out a way to incorporate the stock parking brake drum.
There's nothing bad about the stock one, it does it's job perfectly. If your's isn't then you need to service them.