Hi Samzo. For a bearded dragon, you'd need the following equipment:
Basking lamp
UV light
(You can buy bulbs now that do both, and last much much longer if you're willing to pay a bit more)
I prefer a calci-sand substrate (proper calci sand, not coloured)
A minumum 3ft vivarium, preferably 4ft
A small amount of wood/foliage/whatever shelter for him/her to hide under, once they get used to you they rarely hide anyway, they love people.
One thing people often do is place a water bowl in the tank with them. For almost any other animal, i'd insult you if you DIDNT, but these guys I do not recommend it personally. Bearded dragons are able to 'drink' so to speak, through their anus. They rehydrate this way by sitting in their water, which also gets filled with as a result, making the water unhealthy very quickly. Instead, spray them lightly towards their head, you'll see what those grooves heading towards their mouths are for and why they are a successful desert species. The grooves are drinking channels that collect dew and direct it to their mouth to drink. Beardies LOVE a bath, especially at shedding time. Bath them at least once a week and the beardie will think you're it's best friend.
As for a website that sells it all, it's tricky. So many places give not-necessary equipment to up the cost, and others dont give the necessary euipment at all. If possible, it would be more productive for you to buy from a shop/specialist. Also, keep your eyes open in free ad papers, I see alot of complete setups WITH dragons going for very cheap, but make sure you inspect everything, especially the animal, very carefully before purchase.
Good luck