Hmm.. doing vector art of SNK artists is gonna be close to impossible, like I'm thinkin a good 6 hours at least a piece on each character. Those artists draw much, much differently than Capcom artists, and although I've seen some cool Alpha artwork done in vector format, Capcom aritsts tend to make really thick outlines on their characters and use pretty plain tones. SNK artists like to use as much color as they can I've noticed, well at least up until Neo Geo broke up and they lost their best artist to Capcom.
I'd say do a search online for "King of Fighters" artwork gallery on like google or something, you'll probably be able to find some good stuff there. There was also a bunch of king of fighters comic books, if you can find pages, you could probably nab some pictures to turn into vector graphics from those.
-Luke