lift or level 09 2500HD

i currently have 245/75R16 and want to put a bigger set of sneakers on my rig but will need to alter the height to accomplish a larger size tire either 285 or 35's. i am a little nervous about doing a 6" pro comp lift because i heard that once you install it that there is no going back since cross members have to be cut. i do know about the other option of new torsion keys to level front end. has anyone done either of these methods? and what can you recommend. i am leaning towards the full lift (if your gonna do it go all the way) but maybe just leveling will sooth my itch for bigger tires. just don't want to settle on the leveling and tires to find out that i shouldv'e just put the money into the 6" lift and 35's. i also will need to find a reputable garage to do the mod and have had no luck finding one with any lifting experience in the MA area. PLEASE HELP !!!