vinhyangWhat do you mean proprietary my english is bad so i don't understand.
It means a front panel connector unique to Dell that will not mate to standard case cabling. You would have to fashion your own connector.
You're better off using a third-party motherboard like the Foxconn I linked to. However, it's possible to use cable ties to bundle the power supply cabling neatly, as I did with my XPS-7100 homebuilt (Asus mainboard, Seasonic power supply). It should be easy, unlike what I found necessary to install a Foxconn mini-ITX mainboard into an HP Slimline case.