I've always found this site here as helpful when looking for some shops.
Repair Shops Specializing in Porsche | PCarShops.com and then you can Google search reviews or post them here for people to let you know their thoughts. Also, can read up on more info about the IMS here:
Porsche 911 Carrera IMS Bearing Replacement - Pelican Parts Technical Article. Gives you an idea of some good products to use as a replacement as well. Good luck!