Advance ICN-2S54 designed specifically to run 1 or 2 - F54T5 lamps. Osram-Sylvania, GE, Howard, and a few others are also making them. ATI is
marketing a ballast as well. The key is: F54T5--the lamp type. Though there are several manufactures making them, IMO, and within the Electrical field, Advance is considered the most reliable. Avoid Fulham Workhorse, and IceCap ballasts, as they are not proper for the application. (Improper current limiting and improper start type.)
http://www.1000bulbs.com/product/366/BA-ICN2S5435I.html