That design is actually quite good for bobtails in Perth. Yours is about the minimum size you would want to use with an adult. So, as you have said, provide different hide spots and objects that the lizard can spend time investigating. Also make sure there is always fresh, cool water available. I am certain you will but it does not hurt to state for the sake of others reading the thread. In spring and autumn you would put them out late morning to midday and in summer early to mid-morning. Please note that they should never be left entirely unattended for the time they are in full sun. Regular checks are recommended, most particularly during hotter weather, to ensure the lizards are not getting over-heated.
If you are able to give your lizard exposure to natural sunlight 3 to 4 hours a week, you will not need a UV light source. If not, then bear in mind that lizards expect light and heat and UV all in the one package. So if you are providing a separate UV source, it needs to overlap with the basking lamp, as synthesis of vitamin D3 in the skin is only efficiently achieved when the lizard is at its preferred body temperature.
If you are keeping the animals indoors, there is no need for supplementary heating at night. I have a good mate who keeps his in a similar container with no artificial heating but daily exposure to sun when available and nighttimes in the shed. They produced two beautiful babies last summer, much to his surprise. I would simply suggest that you give it a go without any night time heating and see how the lizards cope. If you are not happy then install a heat source for night use. I would recommend a 15W heat cord rather than a ceramic heat emitter. If you require information on how to set it up just PM or check out the threads on it.
Good luck with your purchase.
Blue
... I dont know about a fully grown one tho
