ok
If you really want some advise. I would tell you to go with Ray Kosby's Impossible Card Magic. Ray is an incredibly creative magician who has come up with magic that is still too hard for most of us to believably execute while still looking magical. Every effect on the video is visual, magical and well thought out.
Now don't get me wrong, The Jerry Andrus material is awesome too, but you WILL lose sleep trying to master the Kosby material. You guys think ClipShift is hard, wait until you try Raise Rise.