After reviewing the instructions for the bodylift, I did not think it would be that big of a deal. It is more work than than any body lift I have ever done, but if only a couple inches are needed for better clearance, the price makes it worth the time. I am tool maker by trade and have full access to an aerospace fab shop, so it would be no big deal to modify the front or rear bumpers and still be able to tow when I am done. I understand not everybody has these capabilities, but none the less, there are plenty of fab shops around the country that would weld the rear bumper so it would be safer for towing.
I would agree that with +18 offset there would be way too much cutting to make them fit, more than likely would actually have to cut the front bumper cover where it would be noticable.