I was thinking of holding off on getting rims but I ended up blowing a tire on the freeway (135s are still fine) and so now may be a good time to get new wheels.

I'm torn between the two:

17x8.5 ET40 with 255/40R17s

OR

18x8.5 ET45 with 235/40R18s

I would like to go to a square set up and I have chosen the two tire sizes for the respective wheel diameters due to the similar prices of the tires. I know there's a group buy for the 18s right now so the overall wheel prices would be very close to similar.