I'm replacing my stock (staggered) 17" wheels with 18x8.5j square setup on my 2013 4matic sport. Stock springs in front (there's virtually no fender gap as it is) and I'll be lowering the rear about 1" - 1. 25." I'm looking for the best balance between comfort and performance while minimizing risk of bent wheels or blown tires. My tire preference is Continental Contipro Contacts. Offsets will be 45 front/40 rear. I'm considering the following tire options (F/R):

1) 245/35/18 square setup
Ideal for me to have a square setup but not sure if they'll fit in front, also concerned about such a small sidewall

2) 235/40/18 / 255/40/18
Concerned the size disparity will cause ESP issues, also bigger rears might look funky. Rubbing issues in front?

3) 235/40/18 / 255/35/18
Opposite problem as above - smaller rears although the size disparity is less at the expense of less sidewall in rear

4) 225/40/18 / 255/35/18
Closest to equal size but I'm concerned the fronts will be too narrow for the rims.

I'd appreciate your comments, suggestions and experiences.

225/40R18 will run on 7.0”-9.0” rims.