Best thing to do is come on over to the Swedespeed forums and post in the s40 thread. We can answer your questions over there =).
What I can suggest for now is look for a T5 rather than a 2.4i because it is similar price point and huge difference in power. If you are looking in adding the OEM bodykit to the car, it is discontinued from many places so it will be difficult and expensive to find one. If you are planning to mod the car, be prepared to be frustrated and spend a lot because there are very limited suppliers.
Here is some inspiration =P