If you are looking for some more opportunities to test the limits of your car with an instructor, some track days with your Porsche Club is always a quick weekend away. It's also a good chance to drive some great tracks.
I'm not too big on Autocross.

Dave

 

Depends on what you want to achieve. PDE is great intro to learn the capabilities and limits of the 911. It is an introduction to car handling characteristics, driving line, heel toe etc., mostly for 911 buyers and entheusiasts not racers. As you progress, Bondurant can't be beat. Take the 2-3 day advanced course which will take you to the larger configurations at Firebird raceway, and more individulized race line strategies. Most drivers that attend end up refreshing every 3-4 months. Incedentally, all their instructors tipically race or coach racers... Darren Law still instructs there as his schedule allows. Have fun.