The mag is a decent pump. Mine I did not ahve to clean like CeeGee..not sure what was up there, but I will say that although it can be run external, it's life will be reduced. If your looking at pumps to run externally, take a look at the panworld pumps. decent bang for the buck, quiet, and reliable..plus they make smaller sizes for the flow your looking for.
Nothing worng with a sequence..bnut usually they are more than you need (as you found out).