It is also worth thinking about how you mount the pump in the case and take into account the thickness of the rad + fan, as they may block off mobo connectors etc. I got caught out by both and it made my build difficult to complete.
I think you have to use a bracket attached to the case to hold the DC pump, as I do not believe it can stand by itself as other pumps can. That restricts where you place it, unless you mod the case. You can see why people go for the Pump/Bay Reservoirs combo if the case is big enough.