I wanted to use a sharp UV point light source, so after going through various options I chose a module named EP-U4545R-A3_PCB. It is an LED already soldered to a star-type heatspreader. The specification is as follows:

• 5W power
• wavelength in 390-410nm range (396nm as measured by the seller)
• Vf 6,8-7,2V (two LEDs in single package)
• 120 degree lens

The wavelength is suitable for the UV soldermask/paint that I am using. 120 degree lens allows to cover a wide area with the UV light, minimizing potential hot-spots.

5W is also quite a lot of power for a small LED module like this one, therefore an additional heatsink must also be attached to the metal heatspreader. I glued one with some typical single-part white heatsink glue.