Once again I agree with Peterson......Many people in here have 19's and come on I mean if you want the 19's get them and if it rubs a little then fix it! Damn for reals though...When I had 19's the rear would slightly rub but I just rolled the fenders...no to hard to do!
And not trying to be a dick, but look through this forum. Go back through old pages. This topic has been covered in extreme detail. There are pics of other people's cars, specs for offest and all that, and it covers 17's, 18's, and 19's.
It's there, just take some time and look. It's not worth going through it again.