I figure i would not need to get a rear bumper (because of the tail), but the front and side skirts might not be a bad idea instead of lowering the car?
Link to front bumper: seems to have a front air splitter on it as well
Extreme Dimensions OTG Body Kit - Front Bumper for 99-04 Volkswagen Jetta at Andy's Auto Sport
As far as transmission gearing it could use some lower gears, it runs about 3500 RPM at 70MPH, which seems really high to me.