What is the standard wheel offset for a sapphire cos 4x4?
I have a mate who runs a tyre/alloy store he's going to let me try some wheel/tyre combo's to see what looks good and more importantly what fits!

So far the plan is use 25-30mm lowering springs but to upgrade to coilovers next year. I'm rolling the arches to give a little more clearance and going to try 225/40R17 or even a 235/35R17 on the rear.
For the front I'll settle for 215/40R17.

Will the slightly different tyre sizes affect the diff's at all?