You live in Zenmervolt's area, If you go for the Porsche, talk to him. He drives a 924.
There is required maintenance on a 89, 944S2. So a documented history is a must and at three owners
that history can get pretty thin. For the Porsche two owner only for me.
The Porsche is the better balanced of the two and will do well in wet conditions.
The MR-2 na can be easily modified for more hp, does not suffer from neglect and is desirable.
It will get tail happy in the wet, has less storage space and a cramped cockpit for those of us over 6'.
I would go for the Porsche myself, as I do all my own repair but for paint & machine work. (968 coupe

)
As a daily driver you can neglect the MR-2 and still be OK. Its a toss-up if you gotta ask
NOTE: halik I've been researching 944S2 and 968 for the last month. If you want the links I have
PM me.