I need lighting for two 20 gallon long verticals. That is, they measure 30" vertically. Im gonna have bromiliads, Dischidias, Hoyas, and some Orchids. The two tanks will probably be placed side by side, one housing a green tree frog and the other will house two D. pumilio 'bastimentos' both of whom do well with temps up to the low 80's.
I don't understand these lights!!!

AHHHHH!!

I need help.
Tell me, are these good?
http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=11382&N=2004+2032+113345
I could probably fit in two of each on top of each tank. But then I would end up with about $100 worth of lights, and probably too much heat. THese are compact flourescents, so I'm guessing they don't put out too much heat, right? How do they compare to power compacts.
Why does everyone want power compacts? Do they sell power compacts small enough for my tanks? And why are all these power compacts so expensive? The only one's I've seen at aquarium stores are over $120!!!!