275/45 0r 275/40?????

[atm70chevy]

I'm just about ready to get new wheels and tires. I have finally decided on my wheels and need some help with the tires. I was looking at going with 275/45/18's but they seem to be a little harder to find and a little more expensive than the 275/40/18's. Is there much difference in the sidewall height between the two? I really want to avoid the rubber band look if I can. Advice and opinions will be greatly appreciated!