Chris,
I like the look of the staggered tires F/R too, but I think I'm gonna keep it simple and run 265/40R18's all around. I was considering going with a Goodyear F1 Supercar 255/45R18's front and 285/40R18's rear, but they appear to be asymmetrical and would make running a spare complicated. Walmart also offers free mounting, $6.50/ tire balancing, and $10/tire road hazard warranty. I know 18's would be special order and they wouldn't be able to immediately replace a damaged tire on a road trip, but it's nice to have the coverage on what are normally expensive tires.
Geno