The minimum recommended lift for 31s is 3". You could try and put those tyres on stock suspension, just don't use curvy or bumpy roads.
As for 8" wheels, that's what I've got, and the large offset makes them stick out, but I've got 4½" of lift to cancel out any rubbing. If you got some wheels with maybe ½" more offset than stock, that might work.
You're best sticking to 235/75R15 with stock suspension.