I installed my 5100's last weekend and here are some tips for anyone else doing them yourself. I would wait about a week after installing them before having the alignment done. It may take a little driving and hitting a couple of good speed bumps to fully reseat the springs in their seats. After I did mine I set them at 2.1" and had 2 3/4" lift after driving it for a couple of short trips. After another day or two they settled down to right at 2 1/4" of lift. Then I got my alignment.
Also a quick note, if your doing them yourself, the coil overs only go in one way. Pay attention to how it is sitting (large flat side tward engine) when you pull it out. It will only go in the same way and it looks almost symetrical unless you look closely at it. That caused me a bit of frustration but other than that everthing went smooth. I suggest downloading the RoughCountry instructions for installing their leveling kit. It will give you a very good idea of the process.