For UVB lights, best thing to do is get a 4' double florescent shop fixture. To simplify things, make sure it already has a plug attached. Otherwise, you have to wire it yourself to your home power or a power cord. The wiring itself is easy, all you do is connect color to color (ie red to red, black to black, white to white) but it's better to have the plug as you can connect it to an indoor/outdoor timer so the lights go on and off automaticaly. (this si really nice if you want to sleep in and not have to worry about turning the lights on for your dragon, or the heat).
How I set up my two tube fixture was a Repti-glo 8.0 UVB and a full spectrum normal light tube. This I found ensured good light intensity in the cage and provided more visible light to enjoy your dragon. You can also jsut put in two uvb 8.0's in the fixture, increasing the available UVB for your dragon, but teh cost of these bulbs does add up when replaced every 6-9 months.
I suspended the dual florescent light fixture about 6" from the roof inside the tank. IT was still high enough above the basking light the dragon couldn't reach it but low enough to give her the best explosure to UVB rays.
For a basking light I used an outdoor flood light bulb, 125 Watts. I attacked a ceramic light socket (had to manually wire this to a plug, which was a bit of a pain but not overly) and mounted it so it was attached to a hole in teh wire mesh covering half of the top of the cage (in retrospect, it would have been easier to mount it to the wooden side, but the florescent fixture took most of the room. Next time I build a cage, teh top will be solid wood, with the front and sides screened or a smaller screened area on the roof so I could mount the lights to wood instead of wire mesh).
The basking spot itself was a large wide piece of driftwood. This allowed for a nice gradiant of basking temps, from about 120F down to about 95F. I think it's very important to have large wide basking areas under a flood light, so the dragon can choose how hot he wants to bask. They take the higher areas during morning, and right after feeding, then move to cooler areas later on in the day.
The tank should have a cooler end, dropping to about 75F during the day and as long as 65F at night. Nighttime heating really isn't necessary unless your home is prone to getting much colder than 65F at night regularly. If it does get cooler, you can either add a ceramic heat emmitter for nighttime temps (still should not raise it above 75F though) or an undertank heater. Night time heat should be set on a different timer than the day time heat/lights, so they only come on at night, and are off during the day. Visible light should not be used to provide heat at night, there are night time bulbs available, usualling red or blue, but not 100% sure these actually are not seen by the dragon. It is very important to have a solid photo period of roughly 12-14 hours daylight during teh summer, and shorter perods during the winter (especially if you want to brumate your dragon, though this isn't necessary. Dragons often go into brumation without any change in lighting or temperatures, I think in this case, they are getting cues from the windows within their line of sight).
One last thing, if you are getting a baby dragon to start, don't put it into the adult cage, this can really stress them. Better to house them in smaller tanks till they are around 15" long then move them into the adult sized tank. I used a 35 gal long aquarium for the first 4 months of owning my dragon (she was about 3 months and 8" when I bought her, and was 15" and around 7-8 months when I moved her into her adult cage).
I have attached a picture of my bearded dragon's cage, don't have the plans for it anymore...I didn't build it myself but drew the basic layout and dimensions on paper which I gave to the family friend who built it for me.

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PHLdyPayne