For a beardie, you need temps of around 140f basking.
To get that, you will need a 100w which packs out plenty of heat. In order to cope with the heat, PLEASE dont use a normal fitting from the local DIY.
The link to the stuff in the ebay sale is what you need, but I would add some fire board between the fitting and the viv.
You will get some say its over kill, but I know quite a few with burnt vivs, and even one or two with burnt homes, due to not dealing with the heat. The costs of these bits is not high, and its sure a lot less than you could be looking at.
As far as a stat, I dont know any stat that works as high as 140f designed for reptile use.
Only problem you may get is not getting a gradient in the viv due to it being 4 foot.
If it gets to hot, pop a 75 w reflector or even a 60w. Thermometer is way more useful in a beardie set up than a stat.