Craig Matthews and Blue Ribbon Flies are the originators of the X-Caddis pattern. Their latest and greatest is called the X2-Caddis, here is the link: Blue Ribbon Flies | How To | X2 Caddis
Another good emerger pattern for caddis is Blue Ribbon's Iris Caddis pattern, here is the link for that one also: Blue Ribbon Flies | How To | Tying Video Archive
Hope these help in your search. I used to use the EHC almost exclusively until I discovered the benefits of a non-hackled pattern that floated in the film. I haven't looked back. I still use the EHC for fast, broken water, but even then I'll try my low-riders first.