A 4x2x2 is a good sized tank. If its made out of anything solid it will be surprisingly dark and UVB lights, especially T8 lights, are not as bright as you would think. Cooper has some good lighting advice for you. I would always recommend lamps over non-light emitting heat sources. Sure, they can live under them and it meets their needs... but these are 'sunworshiping' reptiles, lots of nice bright light is necessary for mental welbeing.
For my 4x2x2 I two 22" T5 lights, one day light and one UVB and a 65W halogen globe inside of a reflective dome. I found the height was too short to use a internally reflected flood light and that caused hotspots in the basking area.