For the money, I would do a rear swaybar. I just did this and am wondering why I waited so long. It has improved the handling of the car - now the rear seems and feels more connected where as before it was a little vague.
Following that I would look at Access Port or a tune - this will get on the road for performance, but beware once you wake up the motor, your wallet may not stand a chance. Basically you can go as far as you want. There are members here with amazing numbers for Hp and Torque and all from a wagon. These engines have a lot of potential.
I recommend that you grab a beverage and search the turbo forum here first if performance is your goal. If handling, then start with the suspension forum. There is wealth of info in either of these that can help one avoid some issues while serving to help you reach the enhancements your after.
Good luck with your plans.