Tire up size on OEM 18" SL rims...?

Howdy folks - I am looking to up size my tires from the 265/60/18 stock. I was thinking of going to a 265/70/18, but would go a little bigger pending on the feedback I get here. I am not planning on messing with my suspension until I need to (like its worn out), no lift in the immediate future, but at some point maybe a small one. For right now I just want to bump the amount of rubber between the rim and road... Suggestions, Experiences - any help would be appreciated.

Thanks......