The only thing extra that you would need is a battery charger
In terms of a camera, my suggestion would be to get the mobius HD action camera, as its small and can record HD video to the SD card. There is also a mount for it on-top of the Emax Nighthawk 300.
Since the Emax kit includes bullet connectors I dont think you will need any extra ones.
If you have any specifics about what camera/FPV TX/RX that you have ordered please let me know and I can offer other suggestions/advice.