Depends on your primary usage...if you want to do some off-road excursions, I'd stick with 16's due to more rim protection form taller sidewalls. Also the ability to air em' down more for better traction.
If you're gonna be primarily street cruising, then the lower profile sidewall of an 18" rim will provide crisper handling, but rougher ride.
The problem is, you can't have it all in one tire/wheel combination...it's all trade off's & compromise.
Also, most 16's are le$$ expensive than most 18's.
I'm not sure if 265/75's would rub on the inside, I doubt it on stock rims...I've got 285/75/16" on my stock rims & I don't think they do...but I did have to do some "hammer mods" on the back side of the front fenderwells to get my 33's to clear. But they're mounted on a rim with more neg. offset.
This may prove useful...
http://www.vehicross.info/modules.ph...warticle&id=32