If you have too many "investors" vs. a few "partners" you fall under SEC guidelines, which is very expensive. Better to set up a LLC and have a few partners, assuming you know people with money to burn.
So many "investors" have been burned over the years investing in films that there is mandatory SEC language that states you are more than likely to loose your investment, etc.
Find people who are willing to invest in you, not necessarily the film as the likeliness of them ever recouping their "investment" much less a profit is very, very, unlikely. If you look at how income flows back to investors in the "movie business" you would never put up money because stealing is so easy and rampant in film "distribution"
Get a copy of Jon Reese's book:
http://www.thinkoutsidetheboxoffice.com/
for a look at how to at least attempt to recoup your money by doing a DIY or hybrid-DIY distribution strategy.
Good luck!
Malcolm
http://www.malcolmproductions.com