you need UVA for leaves and UVB for flowering. Depending on tank size and local temps, you can use compact florescent. But they give off no heat really, if you go for a hood unit with a tube floresent you want 6500 kelvins for plant growth. Most full spectrum lights have it in ratings. But if you go for a cheeper aquarium(fish) bulb, you need to pay attention to what you're buying. These tube florescents get warmer. Possibly up to 80 degrees on a 5.0 bulb. I would only go that route if you need the heat in winter or run AC in summer.
Darts can be kept at room temp.