And here is the renderings with the laing d4s in series. i set it up to make the tubing the shortest physically possible. You will need to turn your rad around though sothe barbs are facing the other way. (not to the other end of the box, but just to turn it around to give it more room to route the cables). The d4's are turned opposite directions to one another in an effor to make tubing shorter. the way i have it setup your system would go:
pumps > cpu > gpu (if u have gpu cooler > res (if u use one) > rad > and then pumps again.
I should note that measurements are accurate down to 2 decimal places and everything was done in millimeters. So its pretty damn perfect. The only thing i didnt really take much time on accuracy was the placement of the holes for the 120mm as i dont the rad on hand to measure with.