You don't have to regear right away, the 4.88's will work better with 35's than the 4.10's did with 33's. I wouldn't regear until you are ready to install lockers, then sell the 4.88's to offset the cost of the 5.29's.

For tires I would go with either MTR's or BFG MT's, if money allows the X-terrains are a good tire as well.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed