a random question, anybody knows where one could buy those white 6 pins pci-e receptacle attached to the PCB?
If you mean the 6-pin PCIe header (Molex part #45558-0003) then Arrow has the best price I could find in the U.S. I just bought 50 pieces at $0.4514/each + shipping.
http://components.arrow.com/part/detail/44166981S8005809N3303