Yeah, a lot of the eBay auctions had "Cravat ascot tie" and such in their descriptions. Looking further, it does appear to be a tie tucked into the white shirt part of a suit. Makes sense that I couldn't find one, then. :P
Now off to find a good suit, I guess. Do suits come with the white part, or is that a white dress shirt worn underneath? Sorry if I sound like an idiot, but I'm mostly clueless when it comes to fancy-shmancy clothing like this.