If you are just going to rhino line it, the bumper doesn't need to be in perfect condition. I would pull the existing bumper, fix it with materials that are made for the job (check your local auto paint store, they will have bumper urethane). Then Rhino line your existing bumper.
*Project Yeti* 99 JGC Limited 4.7 w/6.5" Rockkrawler LA & IRO A-arm, Goodyear MTR 35's on MB TKO's, 4.56 Yukon's, Iceland Offroad Bumper/Flares/Sliders, Protofab Rear Carrier, SuperChips, Uniden/Firestick, Flowmaster, Smittybilt 8k Synthetic Line Winch.
My Jeep is Organic - Undercoated in 100% all natural Utah Dirt --- Utah Jeep Crew #49 ~Will
2012 JeepForum GCOTY --- [URL=http://www.jeepforum.com/forum/f197/project-yeti-abominable-wj-1125665/]Project Yeti Build Thread[/URL]