I run 33x10.50 BFG MTs under a 4.5" Rubicon Express SuperFlex lift. I find it to be a great combination.
Trimmed a bit of sheet metal under the flares front and rear. Did not need to relocate flares. Removed the plastic crap that hung under the front bumper and connected to the front flares. Cut front flares and front quarter panel in line with top of bumper.
I run the 15x7s with stock back-spacing. This results in lower control arm contact when the steering is hard over. Not a big deal. Adjust stops or drive accrodingly. Also notice signs of very slight rubbing (mud rubbed off) on the protrusion above the coil spring. Both problems are minor and could be corrected with slightly less back-spacing.
A SYE/CV is a good mod because it is stronger, it lets you remove your rear shaft without losing fluid, and the required higher rear pinion angle keeps the pinion off the rocks. That being said, you do not need a SYE/CV conversion to eliminate drive line vibrations with a 4.5" lift. Just drop the t-case and shim the rear springs so the pinion is parallel with the yoke. You might need to grind the armpits on the slip yoke to prevent u-joint binding at full axle drop.
I addeed and upgraded a few items with the RE kit. Added a drop Pitman arm to improve steering geometry. Upgraded crappy RE anti-sway bar links to JKS quickers. Upgraded purportedly problematic standard RE track bar with heavy duty RE track bar and HD bracket. Overall very happy with the RE suspension and OME shocks.
Don't forget about differential gearing. 4.56 is a good ratio for 33" tires. 4.10 works well too, especially if you do alot of highway driving. Mine orginally had 3.07. I swapped in salvaged 4.10s from a junked four-cyl. When I regeared to 4.10, I found that a 35 tooth speedometer gear put the spedometer within 1% of my GPS.
Steve
http://xjeep.dyndns.org