I run a '94 GT with an auto
trans on autocross courses. We have a
trans cooler and a B&M Transpak shift kit. It works excellent! The shift from 1- 2 will squeal the tires 255/40/17, stock engine, 3.73 gears. Two "problems" we have, do NOT downshift to second until you are under 60MPH, it will slow the rear tires so much they will slide, and we have to use OD on some long straight stretches. The auto also has us chewing up racing brake pads like they are free. We do manually downshift and upshift.
The advantage to a novice is that you can concentrate on driving instead of always trying to properly shift. For the first couple of times, just use Drive and when you find your lines, start playing with shifting.
Your six is rated at 200HP, my eight is factory rated at 215HP. I know the torque is different. Put on the
trans cooler, put in the shift kit (you CAN do it yourself, the instructions are very well written), throw on some racing pads (you can start with Hawk black pads, just for the track), and go out and have some fun!