Needing spacers would depend on what Back spacing your rim is. Note: Using spacers makes the weight of the axle ride differently and could wear out you wheel bearings quicker (I personally have been warned of this). Note #2: I've seen tons of people run wheels with spacers with no problem.
I don't know much about lifts but here is what I know for a fact, You will need at least a 3" lift to fit those tires. Most people running that size of tire have a 4-6" lift.
Body v.s. Suspension lift? Again I'm no expert but I would use only a suspension lift kit. You will need longer front and rear drive shafts after you a suspension lift over 3".
Hope this helps.