I just got a 02 SVTF (don't know much about hop-ups)and was wondering how much an improvment would I get if I got the Eibach Pro-System. I understand why to get it if you have a stock ZX3, but what are the gains if any on an SVT? Thanks

The cool thing about the suspension in the SVT is the awesome handling combined with comfort. If you get an aftermarket suspension you can kiss the comfort goodbye. If you decide to get an aftermarket suspension it will handle like no other!
I've been in a few cars with aftermarket suspensions & they have less roll than my car but they're rough riders. Most cars that ride as well as the the SVT don't handle as well & most cars that handle as well don't ride as smooth.

Thanks for the info. One more question, I have read that you should replace the dampers when switching out springs, would this also be relevent to the SVT? I'm thinking it would be since the car would be lower. I haven't read much about it, has anyone just swapped out the springs on an SVT - comments please.

Yes, this is true. A camber correction kit is also recommended.
A lot of guys don't worry about dampeners & just put springs on it. Its ok for a little while but eventually the dampeners will wear & the car will be really bouncy.