A basking spot up to 35c, thereabouts, using a light bulb is the best heating for a beardy. The wattage of the bulb will depend on how high his tank his, or should I say, how high or low his basking spot is. Whether its the floor, or a log or rock, or whatever you use directly under his basking spot, its that spot that needs to be maximum temperature. And use a spot bulb (with silver frosted/painted reflector on the light bulb) so that the heat can be directed downwards.
For our bearded dragon we used a normal, household 50W downlight. With the glass front removed it will serve as heat and UV - both are crucial for dragons. I had a high rock that he could climb up to get close to the light, and had my thermostat set so that the hottest spot on top of this rock went no hotter than about 38c. Yes the temps do sound a little high, but I had heaps of basking spots at different levels and a temperature of 28 or lower at the opposite end of his tank, so he could move around to regulate his temperature needs.
To avoid needing a thermostat I would suggest ordinary light bulbs, not the downlights. You can get spot bulbs for about $5 at Coles, Bunnings, most supermarkets ranging from 40W up to 150W. Start with a lower wattage and if it doesn't heat up enough, buy the next size up - least they aren't totally costly since you can use others in lights around the house.
Otherwise, there are also plenty of lighting available at reptile/pet stores as well. If you choose to use a thermostat try getting a dimming one rather than one that turns on/off.
As far as UV is concerned, if you can give your beardy access to natural sunlight for 4-6 hours a week, my Bearded Dragon Manual suggests that 4 hours of real sunlight provides same benefits as having a artificial uv light on 10 hours a day.