Increasing the stroke of the engine is accomplished two ways - shortened rod length and increased crank throw - you would not be changing the overall configuration of the engine. There are a few stroker kits out there. What you've done is increased the piston travel and thereby increased the volume of each cylinder.
If you're looking for info on stroker motor performance, Hot Rod Magazine did a pretty good article on the effects of displacement on performance in January (yellow Cobra on the cover). Just skip over the article on the 03 Cobra v. STi, it's a waste of space imo.
Jay