Personally, I do not use UVB lighting on my skink (BTS). We've had him since Jan 2008 since he was a baby, and he has grown tremendously, is still active, eats readily, and has never shown any signs of any kind of ailment that is often associated with lack of UV lighting.
It is my honest opinion that skinks (along with several other species of lizards) are perfectly capable of thriving without UVB, providing their heating and dietary requirements are met. This is still somewhat of a controversial issue; I'm only going by my own experience as well as others who have kept skinks w/o UVB.
However, I still agree that while it may or may not be a necessity for them, they still benefit from it regardless. Do with this information as you will.
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As far as UV lights go, I greatly prefer the mercury vapor bulbs (MVB). However, these bulbs only are available in 125 watts and 160 watts, both of which simply emit too much heat for smaller enclosures.
My next favs are the UV coil bulbs, which are essentially a UV light that can be used in an incandescent fixture. These are great for providing UV in very small enclosures.
Then there are the T-5 florescent fixtures. These are much slimmer than a normal T-8 or T-10 florescent light strip, and also, are 2-3x more intense in their emittance of UV than them as well.
Remember that with any of these bulbs, you need to replace them approximately every 6-8 months, as their ability to emit UV radiation diminishes over time, essentially leaving you with just a very bright bulb.