In addition to building an arduino shield, I am also building a full on arduino compatible version.
Boards were made by Seed studio. They aren't as good as OSH Park, but they are cheaper. I could probably pay for them to be made with a higher quality, but I don't need to have gold plated contacts or super flat components. I'm not using surface mount components right now.
Plugged it in, and it works! Hooray! I learned a couple of things from making it and testing it. Next version, 0.9 (which is completed on upverter here) will have a few tweaks to the board, along with the headband board, so that it is easier to make and add the cables to.
Now I just need to build enough of them to play test. I'll then have to make some cases, which will be the next part of the build. Along with updating the code. Right now, there are three classes that are functional: soldier, healer, and a base.