Depends on how hard and how far off of the trail you’re planning on going wheeling.
The most important thing you should have is a tow strap and someone else to wheel with.
As far as spares? U-joints(you’ll also need a tool or some way of replacing them in the sticks), fluids, various hose clamps, fuel pump, an axle shaft if you’re feeling unlucky, spare front & rear diff gaskets, serpentine-belt , alternator, water pump, t-stat & gasket, various fuses, … and don’t forget the duct tape and JB-Weld.
My favorite tool: 6lb. Sledgie!(BFH)