Kartman had my old TSW Pace in 19's...immaculate they were and well worth the cash he paid me for them! []
Fee, it ain't about the wheel size when you get to 18's or 19's, but the tyre size. I know people who have SOMEHOW got away with 18's and 225/35's, but many more people can get scrubbage on the rear's with 215/35's as i am getting just now. With the 19's on me old RB5, i had to roll the rear arches(went a bit far n crcked the paint...doh []) and it was lowered on H&R springs.
Scoty eventually had Leda coilovers IIRC dropped till the car was scraping along the floor, inner arches were rubbed away to feck and had 19" OZ Supperleggras with 215/35's on them.
Nowt wrong with the handling of the car, except if you were hard round the corners, the wheel could very well get in contact with the asphalt.
If you want looks, go for 18's with 215/35's and if it's sheer driver enjoyment, 17's with 215/45's. 45's are easier and cheaper to get a hold of.
You can't run different sized wheels/tyres from front to back, otherwise it'll handle like a boat, as it's 4wd...keep that to front or rear wheel driven cars. []
Any more questions, just ask. [H]