I decided to buy a Halogen bulb since it is cheaper then the petstore ones, it was 73watts and what I've noticed from using is the intensity of the heat is not directed downwards unlike the heat bulbs from the pet store that are $23 more I'm just wondering if there is a certain brand I have to use? or if there is an alternative. I do live in Australia if that helps.
They aren't all equal really. Some of them are energy saving versions which don't put out enough heat. The reflectors built into them are different and can cause different spreads. I like PAR38 and BR40 bulbs because they provide a nice wide beam. I use a GE PAR38 90w bulb for basking which works well. It is 1790 lumens which is reasonably bright. Try to get one that has as many lumens as possible. I'm not sure exactly what you have available. I'd guess that Bunnings or Mitre 10 would carry something similar.