I run the M608's @ 265 width and love them. They sing to me at freeway speed IF the window is down. I run around the same rear weight on my axle as you and I'm so confident in this tire, I don't bother hauling around a spare any more.
I got my Rickson wheels off craigslist. It took me 2 years to get the beauty rings but looks much better with them, it was worth the wait.
90psi rear, 72psi front.
My 2006 Dodge Ram short bed w/4wd and diesel required a 2" leveling kit on the front for the tires to clear a full wheel lock to wheel lock on the steering wheel. Otherwise, they rubbed a very little bit just before lock.