If his Sig is correct: Lian Li PC-A10B
I am using LED´s from http:www.leds.de
direct Link: Is here to find *click*
But the most important thing you need to know is the nm-value (here 370-375nm)
http://leds.de/daten/wellenlaenge_tippinfo.jpg
the lower it is, the better the effect. The higher the value is, more purple light you will get. (Standard is not good - 395-400nm)
I needed at least 8 LED's of the better quality to get that effect.