Never liked the idea of a PFO ballast, sure it's nice to throw more power at your bulbs and guess what they turn brighter, but then your bulbs don't last as long and you use more electricity.
Anyways, this is the one I bought, it's a replacement ballast for oceanlight pendants, but that doesn't seem to matter, simply hook up a cord from your socket to a standard 3 prong plug and you're set. Best thing I like is that it's a dual ballast, at the price of most single ballasts. Only downside I've found is I can't independently turn on each bulb since there's only one power cord, but you probably could hook up some system to do it since the plugs from the sockets are standard power plugs

http://www.customaquatic.com/customaquatic/itemdetail.asp?subcatindexid=lt-rbal-m2&itemid=LT-AB72300