67 Wheel fitment help

[LDB]

I'm finally ready to pull the trigger on some new wheels/tires for my 67 Camaro. Stock 10 bolt rear with drum, stock disc breaks up front. I did have the rear leafs de-arched 2 1/2". I'm going with the Ridler 695(cheap). I've searched the forum and there are so many different opinions on wheels size. Can some explain the benefit of an 18" over a 17"? Our roads are brutal here so I'm a little concerned with 18". I found these wheels on sale and I'm ready to order but I want to make sure. I want the wheels to tuck nicely and tires need to fill the wheel wells.

F- 17x8. 4.75" BS. 225/40
R- 17x8. 5.5" BS. 255/40

OR

F-18x8. 4.5" BS
R- 18x9.5 5.5" BS


Can some please tell me this is correct?

I would consider 18" if there's a benefit.

thank you