I would inspect the T belt very carefully before firing it up unless you know when it was last changed
Plan an at least another $1000 for basic stuff (you doing the labor) and you will have a great car.
Auto or manual? If a standard and with that millage I would suspect it may have the original rubber centered clutch disk. IT will fail leaving you with a loose / clunking drive line. Not catastrophic but it will need to be addressed. Than just go through it. These cars live best with preventive maintenance. Yes the water pump and belts are a bit of a pain but I would rather do a 944 than a ford escort. Oh ya there is an update for the water pump that involves guides for the timing belt, a new roller and some cutting of the plastic housing around the belt. Again due to the low millage I would bet you will need to do this.
When you crank it does the tachometer bounce? If no you will probably speed and reference sensors. Or at very least they will need adjustment. Inspect the connections and the cables as they tend to deteriorate. Order replacements but from a from a 87 535 BMW (1/2 the cost of OE Porsche) The only difference is that the cable is a tad shorter
If you have not been there already Clarks Garage is a great resource as is the forums over at Pelican Parts. If you need more info on things just PM me or email I have quite a library of sources for info and parts
Oh ya once you get it running these cars like to be driven. It seems that when ever I park my car for a week or more it seems to develop problems. Drive it regularly and no issues.