Do some searching on the forum about what it takes to run a 4" lift properly. For 33s you could run a 2" suspension lift and 1" body lift.
For a 4" suspension lift you may need the following, adjustable front and rear trackbar, rear tb bracket, adjustable control arms, sye kit, cv driveshaft, extended brake lines, etc...
Take a look at the MetalCloak TJ Lite 3.5 complete kit http://www.metalcloak.com/TJ-LJ-Wran...ARB-p/7160.htm
. I would consider this everything you need excluding sye and cv drive shaft. Not saying you should buy the kit, but note all the different components. Mix and match brands to your liking.
You may want to reconsider 18" wheels once you see the price difference between tires for 15" and 18" wheels.