I would suggest getting a single 48" reptisun 10.0 to run most of the length of the tank instead of using two smaller bulbs. It'll cost you less and cover more area.
I'd also ditch the red lights, they're pointless with dragons. During the day your dragon needs lots of bright clear (not coloured) light to thrive. At night there should be no lights on in the tank as these can disrupt your dragon's sleep. At night you only need additional heat if the temperatures drop below the low sixties, otherwise the cooldown is natural and healthy for them. If it does get too cold at night, you could use a ceramic heat emitter to bump the temps up a bit.
Just a heads up, you can use a regular lightbulb or a halogen flood light as heat/basking lights in your tank - no need to pay more for a petstore heat bulb. All you need is something that puts off bright clear light and enough heat to get the temperatures where they need to be (100-110*F basking spot, 80*F cool side).