I don't think those lights are very good for growing plants. I would wait until you get the new tank. If you are looking at LED look for Finnex, or the new Current USA fixtures, they should be affordable options.
I have a 13 Gallon kit hood w small 0.5 LED lights. I know it's very low so I'm undecided if I should wait to invest when I get a 30 gallon, which might be in about 6 months. Or if I should add lights to my current hood (hopefully I can take it to the bigger tank)
So I found these and wondering what might be a better option for adding more plants.
http://www.marineland.com/Products/...bright-blue-led-aquarium-lighting-system.aspx
http://www.marineland.com/Products/...twater-reef-aquarium-led-lighting-system.aspx