You need to start looking for a local independent repair/performance "Porsche" shop. Check around, or contact your regional PCA or POC president and see who support them in you local area. Stop in an talk with the guys, start to build a relationship with them! Any shop can take your money, what you need is shop who takes care of your Porsche and is concerned with your safety. He should point out items/issue that need to be address. And will have tips on the maintenance that you want to handle; along with his input from him working on Porsche's of all type.
Art