that offset is fine, if you go any lower than 1.2" might rub, but as the car is you are fine. As a matter of fact, it will give the car a nice, bolder look
There's a person with 18x8.5, 42et sportec mono10's that didn't seem to be having any problems. I think you might even be able to fit 19x8.5's, 42 et if you don't drop that car more than an inch or so.