Going to use power heads for most of the flow? If so, being energy efficient with 5X DT turnover going to need 2000-2500 GPH, after head loss, and any flow diverted for reactors and such.
I would start looking at pump/plumbing calculators to see what gets you to that output. I'm using a cheap Jaebo DCT, but my run is far shorter.
Take a look at Sicce Syncra 12 or 16. Website has head loss charts. Need to factor all the bends, size changes of pipe, to see which one you need.