You don't have to but I would recommend it. If your currently mounts are in good shape (which they should be on a 2006) then just go with a JKS MML. If they are not in good shape, replace them with some Brown Dogs. I replaced mine with Brown Dogs and it was super easy.
'98 - 4.0 - HP30 Front, 8.8 Rear, 4.88 -1.25" BL, Brown Dog 1" MML, 3.5" RE springs and crappy shocks - 33" Goodyear Duratrac on Crager soft 8's 15x8 - Toys By Troy front roll cage and custom welded rear roll cage addition.