For 33s you'll want a 2.5" lift ideally, that will be the perfect size. You could put the 33s on without a lift, but you'd have to extend your bump stops quite a bit to keep the tires from crashing into the fender when off-roading or anything like that (even big pot holes in the road).
There are a lot of lifts to choose from. Quality lifts include [USER=18098]@Clayton Off Road[/USER], Currie, Savvy, AEV, and several others. Stay away from Skyjacker and Rough Country, which are low quality, poorly designed lifts in most cases.