That connector looks like a JST XH series, assuming the one pictured is actually what you need. Digi-key does stock this series. There's a minimum order of 10 on the housings and 100 on the contacts. I have a roll of contacts I can cut some off of if you want, and I may or may not have an 8 position housing, too. If I have the parts, I can make you a cable for $15 + shipping.
Please confirm that you do need that particular connector. Digi-Key's website has some nice pictures.
If it's the board I'm used to seeing (the one arcademvs.com sells), you can also use a HD15 connector for the input. It's wired just like a PC VGA connection. If you have composite sync, it goes on the horizontal line. You can buy a HD15 solder cup connector at Radio Shack for a couple bucks.