Cojack

I have a 2004 fx4 and I just bought a set of 35x12.5 cooper stt tires on 20 inch rims. I am trying to decide what the best leveling kit would be to go with. I am aware of the fact that regardless of what I do there is going to be some rubbing in my wheel wells. Is a 2.5 kit ok or should I really go for a 3? I would prefer not to ruin the underside of my truck, any input would be great.