At the time the original motor list was created, I stuck to items Mike carries in stock since those seem to be the more common ones. Even then, the list seems a bit long. It has grown to the point now that I don't think it'll matter if I add two or two dozen. :)
Just added a diagram to the Lipo Wiring page (scroll to the bottom) which shows how to wire up balancer Y adaptors when using two seperate packs. Currently, there are only entries for Hyperion balancer connectors, but if someone wants the wiring scheme of other types of connectors, let me know...