Tire Sizing Help for 18"

[dbals]

I am thinking of buying a set of Beyern 18" Mesh wheels and they come in a 18" x 8.5 staggered 18" x 9.5 wheel size. I want to discuss the recommended tire size. Ive seen 265/35 on rear and 235/40 on front for this rim set up. I want to make absolute sure I have enough side wall to cover and give some protection to the lip of the rim. I hate when people put to narrow of a tire on a rim. Most cases when Ive seen a 235/40 tire on front its on a 8 inch wheel, this wheel is a 8.5. Do you think its going to cause a problem? I guess my question would be if I should put a 235/40 or a 245/40 on the front and a 265/35 or a 275/40 on the rear?
What do you guys think?