Fwiw, on my setup I have a barracuda that is manifolded off and runs all of my eqpt. Skimmer, chiller loop, calcium reactor, UV sterilizer and my biopellet reactor. I have the tank valved way back but deliver about 1500 gph to it. My pump is 10' below the top of the tank.
Darts are rated at 3600, barracuda is 4600 (or so) and the hammerhead is in the 5500 range.