I get heatsinks in Germany from resellers of this company http://www.fischerelektronik.de/ Look for STRANGKÜHLKÖRPER (funny for English natives)
They have almost every heatsink imaginable. I would say it is like heatsinkusa in the US.
I did my build with those heatsinks, each 60cm long 10cm wide with 2,2cm fins.
Didn't tap any holes. Just kapton tape and thermal compound - hey if growma... does it in it tutorial then I can do it for a lamp that only will be used 4 months.
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
I almost went for a build with cxb3590 and active cooling, it seemed more reasonable to me than paying more on heatsinks then on leds. Many people did build with arctic coolers. https://www.notebooksbilliger.de/arctic ... a87ff6_pla