don't forget tire sizing is very important. If you want 265s on there, good luck. But if you want something like 235 or even 245s, you should be ok after rolling. Unfortunately, I have to say you SHOULD be ok because it's not a guarantee on that - tires rated the same size might fit differently - have a different tread width or tire width - they might be more rounded or square when viewed front-to-back. All of those things play a factor in "if it fits or not"
If you go with 235/40/18s, +45mm, and a roll - I would say you can do that. It really depends on how much you are looking for and how much you want to push the envelope.
6 club has a really good thread with member wheels and wheel/tire specs (along with suspension thrown in there) so you can see what works for the most part.