Can you give me the names of as many vendors as possible who can help
me put on an outdoor film festival in my community? Ideally it would
be someone who could help me "soup to nuts" by consulting on organizing,
fundraising & logistics as well as providing  (renting) me the
sound/projection equipment and the film itself. 

Projected attendence would be 300 people.

I am in the Philadelphia area.

As a theatre owner for the past 31 years, I think that you should
contact a theatre supply and inquire about projector equipment. 
Second you would need to contact a film booking agency to see if they
can get the type of films you have in mind.  Tri-State Booking Agency
in Cincinnati, Ohio is probably the largest in the US.  One Call to
them would get the ball rolling for you.  Their phone number is
:513-851-5700 ask for Steve Zeiser.  I hope this will help you.
Lanny Franklin, West Libert, Ky. 41472