I'm looking at this unit.
http://www.marinedepot.com/Korallin_C3002_Calcium_Reactor_with_Eheim_Pump_Saltwater_Aquarium_Calcium_Reactors-Korallin-KL3002-FICRRA-KL3002-vi.html">http://www.marinedepot.com/Korallin_C3002_Calcium_Reactor_with_Eheim_Pump_Saltwater_Aquarium_Calcium_Reactors-Korallin-KL3002-FICRRA-KL3002-vi.html</a>
Should be ok with the pump on the top.