That set up looks fine.
You won't need a dimmer thermostat for a leo, and only a low wattage bulb so he doesn't overheat - the viv heat is provided by the heatmat.
In fact a light isn't necessary at all if you're placing his viv in a decently lit room. They need to have an indication of the day/night cycle is all. People often use a blue or red bulb to watch their little guy at night.
So if the room is well lit, lighting is optional.
Add a thermometer to keep an eye on your temps, get his vitamins, calcium & bugs and you're good to go.