No matter which one you get. Make sure you have $2K as an emergency fund.
The NA 2.5 is a little over priced but with a new clutch ($2K) it is a nice thing to have done by the pro's .
My choice would be between the NA2.5 and Turbo . If you can have the shop throw in a new water pump/belts/rollers on either one.... for the prices you have listed it would be a good deal... If the clutch hasn't been changed on the Turbo (original) walk away unless you want to spend another $2K.
Either car would be good for another 100K with normal maintenance after this....
This will be your primary mode of transportation so go for the car that has had the most stuff replaced
P.S These engines are solid for 200K easily..............(as long as you maintain them) Also keep looking you will be surprised how many nice 944's you can find in this price range....