Which of these 2 cars should I buy?
I have driven a 98 Boxster and a 99 Mustang GT convertible(not Cobra).
I can tell you now that eventhough I have not driven the Cobra version, the Boxster is going to be 5 times more fun to drive and handle much better with its mid-engine design and light weight. They are also more reliable and have a higher resale value.
The Porsche is the head turner.
Mustangs are everywhere. Rarely anyone actually turns there head to look at a Mustang since they are everywhere. So even if it is the Cobra, it will probably not be noticed.
The Ford is a lot more practical with the back seats and larger trunk. It is also better in rain. The Boxster is awful in rain and impossible in snow. If you need the back seats, the smarter choice is the Ford.
If not, get the Boxster.
I would get the Boxster. I have driven many faster and much more powerful cars than the Boxster, but the Porsche was the most fun. After I drove it a few years ago, I then decided that I will get a Porsche one day.