http://homeharvest.com/lampballastshydrofarm.htm
look at that page and scroll down
says all three types are supported...I'd use a convertable bulb, expensive to be sure. if you use one of the others, you'd need to get both types, if you want to MH for veg and HPS for flowering.
that ballast is really good, expensive and a great warranty, but it won't do both types at once, single bulb of MH
and HPS. only one bulb at a time, so convertible is best choice. IMO
that page also lists some suggested bulb types/wattages
did yours come with the 'all system cord set', or did you have to buy it separately?