I would go with the Porsche.

The SRT-6 is faster and all, but it is an auto.

But if you want something fast buy a corvette.

The Porsche is a nice compromise.

Also, unless the SRT-6 is a roadster, 27k is paying way too much for it. Unless it is new.

I have driven them both, and the Boxter S is much more fun to drive. Nothing like the back kicking out on a WOT 1-2 shift. Plus I also fit in the boxter with greater ease. 6'1" 230 lbs". Maintenance will suck on both of them.