What are you talking about?
19x10.5 +12 is fine with a 305. I bet he'd be fine with a 325 as well with a tiny bit of camber.
19x9.5 +12 will require camber but i see no reason why a 265 won't work, and a 245 certainly will.
Look at this car:
GMR SS-1 Wheels
19x9.5 +15 (+12 after a 3mm spacer for brake clearance) and a 235/35/19 front. He has a huge amount of clearance. more than enough that a 245/40/19 would fit.