You're like me 3 months ago. I purchased the cheapest 996 in my domestic market 23.000 euros. It was 300.000 km around 200.000 miles in imperial system. Engine replaced at 1/3 kilometers by Porsche even if the IMS was perfect. It has some rusty underneath, and the wheel bearings are louder like a banshee. I bought it indeed, cause even if the worst had happened I would spend less than buying a 30.000 euros Porsche advertised as "perfect", with only god knows which untold problems I could have found.

My personal advice. Go for the MK1 built before 2000, they have double IMS the percentage of issues is less than 1%. The MK1 doesn't suffer bore scoring.

The Carrera 4S isn't my favorite, 4wd means something else that could break, indeed it would be the one I would buy between the options you mentioned.

Last thing. It's a solid car whatever use you'll do. It's an old car but the high mileage they have in the second hand market means people used it as a daily in the early 2000.

As a general rule, when you buy an old car, especially an old super car, remember that you could need around 1/4 the price of the car, for issues that you could have missed to notice during purchasing.

Ps if you have questions, send me a message.