Welcome to EH-Net! I don't know if you have had any exposure to IT Security during your career so it is hard to give you a thumbs up on the CEH as a starting place. If you have some experience in IT security then yes the CEH training would be a good place to start. On the other hand if you really haven't had to much exposure to security then the Security + certification is a better place to start.
Security + a is much more generalized IT security certification where you would be exposed to a wider base of information. CEH training is specialized and concentrates on exactly what it sounds like "Ethical Hacking". CEH begins teaching you the methods and tools used to perform penetration tests. Without knowing more about your background I would personally recommend you go for Security + first then once you get that down move on to CEH training.
That being said as for which training institute to use InfoSec Institute or ChicagoCon that depends on what you are looking for. If you want to just get the CEH certification and move on then I would recommend going with the InfoSec Institute. With their training you could focus on just studying for the CEH exam. You can spend eight or more hours a day in class then go home at night and study some more all week. This method makes passing the test much easier. If you are interested in getting your feet wet and getting some training. As well as talking to and seeing a lot of cool things and people then you would be better off going to ChicagoCon. There you get the "full" package you will get presentations from top IT Security professionals, a weeks worth of security training, and some good nights of drinking with the top IT Security professionals but this "full" package might make passing the CEH test at the end of the week more difficult. Especially the "drinking" part.

Both are in my opinion good options and whichever you go with you should still make it a point to sign up for ChicagoCons conference only option. That way you can meet a lot of the people on this forum and get
hear some great security presentations.
Can you tell that work is really really slow tonight? LOL!