What size Ocean Runner are you looking at? I run a 3700 NW and like it (so far, so good anyway...), same pump as a 3500 I believe, just with the fancy NW. This pump has MPT fittings. You can also get away with readily available fittings on this pump.
I'm in the middle of upgrading from a 75 to a 125 and am trying to figure out what I want to do with my pumps. I currently have a mak4 on my closed loop a mag12 for my return and a mag7 on my Aquac EV180. I think I'd like to go with a larger pump on my closed loop and skimmer and a smaller one on my return. I was also thinking of feeding my calcium reactor and chiller off of the return so maybe I wouldn't want smaller. If I the pumps happen to be quieter and draw less wattage then all the better. I know every one recommends the ehiem for the Aquac so I was leaning that way for the skimmer.
Starting to think these hydor power heads might be a good alternative. Lots of flow, low power consumption, low heat transfer, and I wouldn't need to drill the tank.