Napalvr

I want to get a set of Vossens CVT (staggered,19"),and was wondering how much variance the AWD system can withstand(tire size wise,and give any problems? The factory size of 18" is .2% , should I go with 235-35 and 265-30 or 275-30? I eventually want to lower the car,but haven't seen any 275-30's dropped on springs only(without rubbing, I won't be using coil overs). Thanks if this has been asked before.