I've had a couple lights that were OK for UV but I think the 'most UV' lights are probably modded. I have a 5 LED XNova with, I think 375nm LEDs, that someone did for me which effectively works very well because even with the longer wavelength... it's so low powered that there isn't much visible light.
And I have a button cell lights, one with a 360 and one with either a 340 or 345. They are in the Coast housings that don't have a lens. The 360 is probably the best at detecting... whatever it is that one detects with a UV light.
But the XNova is my favorite.