I say....get the King IFR course, and the Jepp IFR/Commercial course DVD's and book. Do both of them, and read that intensely verbose book. And then, watch the Sporty's IFR course as a review.
Since the material will be in different places with the two different courses, use one course as the 'introduction' and use the other course as fill-in. Then, read that book for the material that you have covered. Some lessons are much better with the King, some lessons are much better with the Jepp stuff. The Sporty's stuff is very good, but doesn't follow the PTS closely like the King and Jepp stuff does.
I did it like that and it worked out for me. I looked at it this way....when you go to an airline interview, this is the ONE rating that your knowledge about flying is coming from. If you skim through the material and just learn enough to get by and pass the checkride, you are cheating yourself. And, if you learn everything IFR like the back of your hand while doing the rating, you will have no problem passing the CFII (oral) checkride with the FAA as an initial instructor rating. It might take twice as long to finish up this rating by doing it this way, but this is the one rating that plays the biggest part in following you no matter what type of commercial flying you decide to do one day. You can never learn too much about instrument flying.