Sorry Rob, didn't see this thread til now. The question is will they fit. Answer is yes they will. (maybe not so well without the Impreza dounut on top but you can get 'em in and where they need to be with a little work)! What it does to the height of the car I don't wanna guess. FYI though if you're looking for stock springs the strongest out there are actually RS rims from 98-00. They clock in at a 157ish lbs rate or so, the wrx springs were 149 or so, SVXs are around 140lbs if I remember the site that had all this useless knowledge on it.
I just found it kinda interesting myself. Best advice is to buy some and find out. You should be able to get a used set of well under $75 or so plus shipping. I know I got our set of 4 struts delivered net day by the kid's day for $100 of nasioc.