Yes you will need the bump stops.
The most common, cost effective, and easy to come by way is the hockey pucks, rubber mallet second, but there are after market rear bump stops if you wish to spend more money with out any other real gain in performance.
For example you could grab a set of
http://jeepinbyal.com/prod-Rear_Bump_Stop_4_-567.aspx and trim them down to your lift height.
But now you are paying $22 for something you can accomplish just as effectively for about $10. Both going with pucks or the JBA bumpstops will require buying bolts/washers/nylon locking nuts... so basically the pucks will cost about 1/2, should be easy to find locally, won't require shipping....