I get my 964 serviced at the Porsche Palm Springs Classic department, and they're very capable, but what they've set up in Atlanta is something more tempting: If you have the bank balance, you can essentially order a "new" classic Porsche. Having had an uneven experience with the independent restorers in the San Diego area, I would certainly explore this option. The biggest challenge with the air-cooled generations is finding experienced technicians to restore them properly... I recall getting my 356A from an independent shop with mis-wired rear lighting, improperly set carbs, and a botched clutch cable. After a three-year restoration. Disappointing. I'm sure the shop rates are eye-watering. But with a stripped base 911 pushing the mid-$120K range, if you can get one, the Classic route may be worth a look.