Replacement parts while motor is out
 

What parts are recommended in replacing during the time of having the transmission rebuilt? e.g clutch, flywheel, pilot bearing, etc.
What's a good indicator to know that it's time to replace the flywheel?
Is SACHS a good brand clutch? No power modifications, just restoration.
I will also be cleaning up gunk from the under chassis body.

I'm new to porsche.
1984' 911 Carrera