Ill have to consult the father now but Im nearly 100% sure that the 944s were all galvanised. Ive driven the 2.5na and it was pretty cool, savage driving positon.
If it were me, Id be goin for the 924 turbo series 2. 2ltr turbo and a much lighter body than the 944.
the 944 engines were totally porsche engines so parts/servicing will be far more expensive than the 924 which is essentially a vw block and porsche head etc
Ill talk to the father, he'l know beter....I'm just trying to remember his ramblings

 

They were galvanised. But check for rust along sills due to careless jacking.

Theres nothing really major on these compared to any other car so check all the obvious stuff like popups work, rear wiper works, switches, etc. A lot of these parts are still pretty cheap though so they can be replaced if faulty.

Check the gearbox in all gears incl reverse and take a sharp turn to check diff for any noises.

The 2.5 engine has balance shafts, if it feels rough they may not be timed correctly, Ive done 2 belts on these and the two were set wrong on pulling them apart.
Some also removed the shafts for more power, but thats rare.
If your not sure of timing belt history drive it home easy and change it asap. The belt is stressed more-so than a normal one because it has teeth on both sides, each side is doing something always.

The biggest pig of a job you can do on these, and the only one that might* turn me off buying one is if the torque tube bearings are gone rough. You'll hear them when cruising under your left elbow. There four bearings in the tube that support the shaft back to box and they are a big'ish job to change. But, they are normal sizes and can be got off the shelf for around 8euro each, the real cost is the time needed to fit them.

 

In addition to the above good advice from the lads you'll find a wealth of helpful owners on the Porsche Club forum in UK and here in Ireland.

 

and if u do buy one and need any parts this lad is in maghera co.derry, breaks afew porsches, 004479 08588962, he 's a sound fella to deal with, here a wee pic of me own 84 944 project[note the usual sill rot ive seen 90/91 944s with just as bad sillrot

http://vagdrivers.net/forums/index.php?showtopic=49619