I'm in Texas, so I can't help with the flight, but I want to be sure you are aware of the changes made a few years ago regarding these types of flights. It is section 91.146, Passenger-carrying flights for the benefit of a charitable, nonprofit, or community event. There are some requirements that need to be met, although they are not onerous. The ones that stand out to me are 1) the flight must be within 25 miles of the airport, 2) the pilot must have at least 500 hours, 3) airplane must have standard airworthiness certificate, and 4) the local Flight Standards District Office must be notified at least 7 days in advance with a few specific items. Go for it, have fun, raise some money, but keep it legal so that the FAA doesn't decided to write this possibility out of the regs next time.
http://rgl.faa.gov/regulatory_and_guidance_library/rgfar.nsf/2caf347ad1d4b35e852566c70067018b/9af6687589a6822c862575ef0070eb22!OpenDocument