as he said, 30" tires will fit already. but if you want a bit of height, you can do a simple budget lift with 1.75" or 2" lift pucks up front and the chevy drop shackles in the rear. this will retain the stock brake lines, stock shocks, stock swaybar links, stock suspension parts and stock steering linkages.
For a mild lift I'd get some WJ (99-04 grand cherokee) factory lower control arms. they are the same length as MJ, but fully boxed and have a much better bushing design. you can get brand new ones or from a junkyard (I paid $25 for mine). you just need to trim the steel bushing to the MJ width. :thumbsup:
plus they have a cool tire-clearancing bend in them. :D