Kraftwerks Performance. Jeff Brubaker who is the owner/mechanic with 25 years of Porsche experience is a MORPCA board member, racer, and all around great guy. He is about 20min North of Columbus (really close to Mid Ohio), but I just took my 996 turbo to him to do my coolant line welds, and he did an extremely nice job. His labor rate is also lower since he only books what he can actually accommodate with quality. He is the only shop I go to. See his work below.
Auto Assets in Powell is also another good shop, and a friend to MORPCA as well. They are well respected, but I have not personally gotten anything past a quote with them.