Grow lights are also plenty available, but does it provide any noticible benefits?
I've found the following grow light which I can DIY;
http://item.taobao.com/item.htm?id=18954804329
Each lamp has five high-power SMD components:
Input voltage: DC 12v
Each power: 1w
Each weight: 11g
Dimensions: 91 * 14mm (screw ear break off 77 * 14)
Sealed: P65 waterproof
Do you need to look for real watts or is equivalent enough?