This is what I use.
For my light fixtures, I buy the 18 inch under-cabinet fluorescent lights at Walmart for $9 each. I pop the plastic covers off and take out the regular fluorescent bulb.
I buy ZooMed Reptisun 10.0 18 inch UVB bulbs from my awesome (sorta) local pet store RockStar Pets. You can also buy them on Amazon or any other pet supply store for $22 to $45. They are good for a year at the most. They fit right into the under-cabinet base.
The back of the light base has holes where you can hang them on screws/nails, but I took these flower pot hooks and bent them into holders. These are only a buck at Walmart.
Then I hang the lights (without the covers) off the back of the tanks so the beardies get max UVB exposure.
I don't have lids on my beardie tanks so I can keep these hanging off the back without a problem. My rescue iguana Sancho keeps trying to escape so I had to put a lid on his tank, but I put the lid over the hooks.
UVB works best if it is not filtered through a screen (either metal or mesh). There are coil UVB bulbs and I've used these before for my healthier beardies. For babies and sicklies, I use the long bulbs. There's a lot of research on the web about what type of UVB is best. If I had unlimited funds in rescue, I'd probably do mercury vapor bulbs (that give both heat & UVB) for my tanks. Since there's no such thing as "unlimited rescue funds," I have found this system to work well for me. I can get a brand new UVB light for under $40.
