I happened across a photo posted on another forum regarding a rear parking brake solution. It's an interesting idea to an on going dilemma that 914 guys struggle with. I don't know how applicable this might be, or what potential (concept wise) it could have, but thought I'd throw it out there.
The photo is a 4 pot radial mount Wilwood caliper that has been modified to accept cable actuated levers. I can't say if the modification compromises the calipers strength, but it is a cute idea. The modified caliper and hardware is offered by Flyin' Miatas.
Andys