The instructions also state that I need "a medical certificate (less than one year) Class 2," but I do not know what they mean by that. My FAA Third Class Medical Certificate is valid through August 2015, and I'm trying to find out whether that will suffice, or if I need to update it, or if I have to get a Second Class medical.

Don,
Its best to contact them directly regarding the license and medical. When contacted them admitting having no medical, since US doesn't require it, they responded that they will get me a medical exam swiftly on the spot, for some insignificant amount of money.
Hope that helps,
GK