Thank you so much for your replies, very interesting about the heat bulb especially as the branded ones are so much more expensive.
But much more exciting is the light & shade method you put the link on to. It makes so much sense for the dragon to be able to self regulate as it would in the wild!
That little link seems to have flipped a switch in me and suddenly things make sense.
I cant wait to get my vivarium and have it all set up just so for my new baby, whoops i mean *coughs and puts on sensible voice!* dragon.