Check my Kushari write-up. You need physiology and history at the absolute least. Technology is good, but you -might- get away without a planet-write up in certain cases. In all likelihood, you'll need to write up a planet, though.
I suggest checking for interest, or gathering people to join ahead of time...and I don't mean gather just two people. I'll tell you why: I've noticed a fad lately, where people start up indy factions with the minimum then no one else takes interest and the faction dies.