The reason why I would recommend the mercury vapour UV lamps are:
-Compared to a neon tube,UV output is much higher (around 40% of the spectrum)
-You do not have to change them every 6-12 months.My lamps are still working and producing sufficient amounts of UV after 2 years of daily use.
-Distance required for the animals to benefit from the UV radiations is longer : 1 ft approx. for a neon light, 2 ft for MVLamps.
-Neon tubes must be connected to a ballast ,so the tube+the ballast varies from £32-45;i pay my UV MVLamps @ £15,and no ballast is needed.
-Heat produced makes an excellent basking spot with adequate temps for beardies,spiny-tail lizards,desert iguanas,bosc monitors,ackies,and similar species.
-No or little additional heat source in the viv is required,for animals living in extremely hot settings,a 25 or 50W heating wire will be ok,according to viv size.