Bulbs don't have to be 'for plants' inorder for them to work well for plants. Two 18 watt T-8 bulbs will put out more light then two 20 watt T-12's.
I run regular old T-8 philips bulbs over my 28 gallon tank and have it filled with plants.
If you don't like the looks of the bulbs, I highly suggest going to lowes and picking up some GE aquarium T-8 light bulbs. They are 5 or 6 dollars a piece and have a K
value of 9325. Very nice looking to the eye and great for plants.