Stay tuned, I'm going to be test fitting a 275/35-19 on a 19x9.5 wheel with a +45 offset. Yes I know this is bigger than a stock tire, but not by an appreciable amount. I'm planning on doing a square set up so I'll be testing front and rear, plus a number of different spacers from 5mm - 15mm to exact the fit.
Was able to find a cheap new wheel and used tire on ebay, before taking the plunge on a full price setup for 4 wheels. This may or may not be the wheel I am planning on going with but what seems to be the best offset for a square wheel given the limited options.