We are currently using a Zoo Med PowerSun 100W UVB (flood light style) in the All Living Things (Petsmart brand) "equivalent" of Zoo Med's Deep Dome Mini fixture.
That is suspended over the black screen lid of the 20L tank by the Large size Zoo Med light stand. ($20 or less if you shop around and/or price match for the large size.)
We purchased the All Living Things brand fixture because that was what was available when we needed it. However, I am less than satisfied with it, because the PowerSun extends beyond the fixture (slightly).
Thanks!