Spectre wrote: The money you'd save from repairs on the Porsche would probably let you mod your 240 enough to make up the performance difference.
That won't take much. The stock handling of the 944 is amongst the worst Porsche has ever put out. It is no better than a stock 240sx in good shape. Although, there is certainly more potential for the Porsche.... but at a price that would far exceed building up the 240's suspension.
As for HP... the base model 944 is only about 10hp better than the KA. The Porsche is also havier I would imagine (I honestly have no idea though). BUT... the turbo 944 is one sick biotch! There is a middle-of-the-line engine as well I believe that is just under 200hp I think. I used to know allthe numbers but it's been many years since I've paid any attention to Porsche.
I'd say go with the Porsche IF you can afford the repair expense on a regular basis, but only if you go with the turbo model. The base model is only SLIGHTLY better than a 240. The two cars are very similar in a lot of ways.