I'm looking for a Script... Where would I post an ad looking for scripts?

I am a low-budget indie film director/producer: Jack Skyyler.
I recently won Best Director at the Atlantic City Cinefest, and was nominated for best writer, but didn't win that.
Anyway, I usually write the scripts for my own productions, but this time I'm up against a script I cannot seem to write. Therefore I'm looking for a script.
Usually when I'm casting a film I use: websites like: Craigslist, StarNow, ExploreTalent, and IMDBPro for finding actors.
I tried using Craigslist to find a script, but I have had no luck on Craigslist.
Is there a good website out there for connecting screenwriters to producers something like StarNow or ExploreTalent? What would you recommend?

Jack