want some advice?
Try to drill a hole right next to the mobo power plug.
And route your cables from behind like this:
http://i125.photobucket.com/albums/p73/aigomorla/IMG_0574.jpg
Take a look at my main rail thats sleeved. I gutted a hole in the back plate and routed all the SATA cables + power cables from behind to the conntectors on the mobo.
It just looks messy because i didnt finish zip tying the loose cords and i have water tubes running.
But i hope you gert the idea.
But on another note: Great job! i bet that felt good too when you finished
π