I agree completely with Fasteddy on the radiator rodding. Wheeling will be putting a lot more strain on your cooling system than any other type of driving, and since it's already telling you that it has issues, you'd better be on the safe side. Get your radiator rodded out, & service the cooling system. I would replace the thermostat, cap & hoses while you've got the cooling system drained, just for peace of mind. Also, make sure your fan clutch is working properly.
I installed the OME shocks & rear springs on my GenII and have been very pleased with them. They give about 3/4" lift in the rear, coupled with a t-bar adjustment in the front, and clear my 33's with no rubbing. Best part is, they ride far more comfortably than the stock setup did, especially on rough roads, but work very well off-road also.