One thing to remember, the Crew Cabs can stress crack from the twisting of that long frame in "off kilter" situations. We've even had a couple of member notice stress cracks after using the Poly Bushing kits from there being less flex in the mounts, and that is now transferred into the cab. I would be very weary about a body lift on a Crew Cab.... it may cause many undue headaches.
I, also am not a fan of body lifts..... the hockey puck ones that are not all that bad.... I just don't care for a lift, body or suspension, but that is my opinion. I have a few reasons to not want a lifted truck, personally. If you do a body lift, keep and eye on the cab afterward
The worst example of a body lift I saw was a post on here, taken from a sale ad local to the poster, id did not belong to a member, of a 2wd Slantnose regular cab. It had what looked like boat trailer rollers at each body point..... You know the ones that are like 4 or 5 inches long and look like a "dog bone"