I think it sounds like a good time. But having it in Sept. likely makes those who would drive a greater distance for a Jeep thing have to decide between the Jeep Rally and this event.
There is a Wounded Warriors Salute Jeep weekend at Rocky Mtn Terrain Park on Aug. 8-9th. Lots of raffles and stuff, wheeling from mild to buggy stuff.
Contacting local clubs in the southern Maine, NH, Mass, and Vermont areas may get you more hands-on help as well as ideas. Living in Maine, I know Maine4x4.org is a large group with a presence in the Lewiston/Auburn area.