33' tyres on my HJ47

[Indestructible 47]

I may be mad but I am thinking about having two sets of rims putting some 33x13.5 inch maxxis mudzillas on my HJ47 for the winter. I am not too fazed by how far they stick out of the wheel arches but will I need a different offset rim when running these tyres and a 2.5 inch lift? I will have factory power steering on it before then so it should still be turnable. for summer I will run 33 inch maxxis bighorns so what offset would I need for them?