You need to fit the PSU duct if your rear fan is being used as a intake, either way it makes it a bit quieter!
Looking nice, although I can not beleive you struggled to fit the motherboard in the case, there is acres of space and not drives to get in your way.
A motherboard tray in this case would not work anyway, 80mm rear fan and no possible blower fan, the v1000+ would cook.