You're looking to grow low light plants in a 20L. You can have either 2wpg standard flourescent with white plastic reflector or the cheaper 1.3wpg compact flourescent with white latex backing. Which do you choose?
I would go for the 2wpg as it will give you more options for plants. With 1.3wpg you're really limited to plant types, although you can do it if you're careful with plant choice.
