not saying its a bad idea necessarily - just what will fit and what wont - I get the need to fill out the arches a bit hence why I went with the spacers myself
Doesn't sound like STI rims will fit from the same year - consider spacers to fill out the arches from a width perspective and retain your existing rims £180 for all four corners (I recently learned spacers are sold in pairs) or go for new alloys with a bigger offset, in this case you could opt for a larger diameter also for a firmer ride and again aesthetics - either way feel free to keep us posted