fluorescent and compact bulbs do put out heat, just not that much. if your vivarium is going to be large(or is it just tall and narrow?), you can put multiple bulbs on the top. do a little research on the plants you want to put in the tank as you will find that there are a lot that dont need really bright light. some need very bright light as well. its not a bad idea to get a thermometer with an outdoor probe and check different places inside the tank to make sure your temperatures are correct