I guess i just saw this and had to post some too LOL
Coil over or springs make a big different in how crazy you can go with the offset and how wide of a tire or wheels.
And do you want to run
275-30-20+285-30-20?
255-35-20+305-30-20? or
255-30-20+305-25-20!
wheels size
20x9.5+20x12?
20x9.5+20x11?
20x10+20x11