On your list the only car other than the Crossfire I would consider is the Mini Cooper S. The Mazda and the Nissan will fall apart long before the Crossfire or the Mini. I had a Mini and loved it, but the Crossfire is much more for the money IMHO.

As far as the power of the SRT, you will soon have a turbo option for the n/a 6spd and auto cars that will get you to SRT performance levels. The build quality of the Crossfire including the interior is typical Mercedes Benz. Yea there are some abused junk out there and I remember seeing a few in my search for my car.