I think what they're doing is awesome, even if the combat isn't based on the historical manuals, since it looks like they have a blast with it, and it's successful at raising funds for various causes. I think they said about 15% goes towards expenses, and the rest towards charity. According to their website they also conduct themselves as a functioning chivalric order.
I noticed that a lot of the armor is off-the-shelf. I spotted at least one GDFB helmet, and what I think was the old CAS-Iberia Spangenhelm that's long since discontinued. Their Sir Edward (small world) I think said his riveted mail was from Knight's Edge, but he might have meant Museum Replicas. I didn't speak with them much (I should have, but I never think of the right things to say or ask when I'm there).
One thing that was amusing was that if the donations for each round of fights made it over $50, they would all line up and do the Wizard of Oz Tin-Man dance.
Ironically I got almost no photo-ops with my own armor there because there were a whole bunch of red knights everywhere.
Anyway, I had thought about the idea of trying to do something similar as well. The problem is that I spread myself thin with all my hobbies.