a uth or flexwatt controlled with a thermostat is best for a leo setup and will work fine with astroturf. if you have to use bulbs than the wattage you need is somewhat dependent on your room temperature. the cool side needs to be around 80 degrees--if you have a herp room that already maintains that as room temp than obviously you won't need to heat the cool side at all, but if your room temp is more like 70 degrees you might need a 50 watt bulb. the same goes for the hot side--the wattage is dependent on your room temp. you may also need to use a thermostat or dimmer switch for each lamp to obtain the right temperature. you'll just have to experiment and see what temps you get with your setup.