I'm not familiar with the tank, but what type of lighting does it require? Incandescent? If it has one of those screw-in incandescent fixtures, you can find small compact flourescent bulbs around 10w, for like $5 at Wal-Mart.
The same exact bulb online will cost you $10 +shipping. I have an Eclipse system 6, and the moss grows fine under the single flourescent tube (8w), albeit slowly.
HTH,
Serg