What do you want as far as light out of this bulb setup?
If you want to get low light out of it .. ie around 23 watts of light you can do this with a smaller ballast.. one thats rated for 2-F32T8 bulbs.. If you want to go with a high light tank.. I would suggest you get more bulbs.. the most you can get out of that bulb is a about 30 watts.. and thats with a $30 ballast..
in other words the best you can do is get a low light tank.. either 1 or 1.5 watts per gallon out of it so you might as well go for the smaller ballast.. its considerably cheaper.. about $8 and HD