I also recommend Matt at TPWS. He honest and affordable -- which I value a lot. My Box is brand new, but I used to take my former 928 into Matt all the time.
I heard he's thinking about moving his shop out to Marc and Melissa's place:
http://www.intlsportscars.com/
At a recent HCRPCA lunch Marc told me Matt does all the work on his 40 993's.
cheers,
Dennis