Well, it still doesn't really give someone an idea of what you can do. Text placed on a background and then compiled into an animated gif doesn't really give anyone an idea of how a comic will look--the panels, layout, etc. Granted, it's something, but I think given the prejudice you're up against, you are going to have to present something a little more to get someone's interest.
Also, I know that there are a lot of pixel artists out there that don't work in Photoshop. Perhaps you should just specify that they should be able to generate art in a certain format (say .gif, .png, etc.) and if you want to import it to PS you can do it yourself.