since your talking about a 4wd you can clear 285s with a 1.5" ball joint spacer from SDORI.com or my favorite source 4crawler.com...

The spacer is inserted between the upper control arm and the ball joint, it requires a little trimming but all this is explained her... Linky

As far as the rear goes stay away from blocks, they cause a bit of axle wrap, add a leaf is too stiff, shackles arent a bad idea. Ill be installing a set of OffroadSolutions shackles in 2 weeks which ill be posting with information on the install, in addition ill also be installing a deaver 3 leaf add a leaf system that should provide a more tolerable spring rate with 1.5" of lift (these are designed for the tundra) the dimensions are however exactly the same.