If you want to make the front of your 996 look more aggresive, the usual route is to go for a GT3 front end (with or without splitter). But this means a new front bumper etal.
Another solution is to take a look at Cargraphics/Parr(UK). They have 2 offerings for the 996, I prefer the "notched" more aggresivemoulding which attaches to the existing front bumper.
It's certainly changed the sometines commented "frumpy" appearance of the 996 front end. It also picks up the line of the factory fitted side skirts on my car as well as the fixed rear spoiler option. With the whole lot in Speed Yellow and Black Victor Equipment Le Mans Wheels, it is a nice looking car
Regards Big Bob