While the art of creating animated lower thirds may seem like a complicated process, it's simply a matter of creating a looping animation, and then designing the still pieces that it fits within.
As to loops, if you have an animated image you want to loop, you need to create what's called a dissolve loop - the image doesn't really loop seamlessly, so you split it in the middle, swap it end for end (so the end of the animation then loops), then put a dissolve between the parts that don't loop (where the cut is).
I generally design my lower third elements in Photoshop, then bring it all together in AE. Bear in mind title and action safe, and whether your comp is HD or SD. If you look at something such as the lower thirds on the ABC Nightly News, notice as you switch your tv between cropped and full HD views, that they've designed for both SD and HD; the main body of the text falls in the SD view, while the design ramps off into the HD space. I'm sure this will change as more and more sets become HD, but they're covering their bases with the current design.
I couldn't navigate to the site you mentioned above, but the above information will get you there. When I'm ready to go with my design,
I output it as a Quicktime Animation with Alpha Channel (Millions of Colors plus). This gives me a file that can then be used in post, or in most any playback server. It will loop as long as needed. I usually output my lower third loops blank, and send along a reference still with the type layout I want, so the CG Ops can get it right. Good luck!
Creative Director / Multimedia Specialist
B&S Exhibits and Multimedia