ehiem, fluvial, renal and other brands are all reliable pump.
you get what you pay for on this items. there are some imitations
made from asia that works the same. the only problem is warranty,
parts, and after sale service.
what i can suggest is the concept of split capacity, meaning
you get two units with the combine capacity needed or larger.
the advantage of this is that you have back up whenever one
bugged down. moreover, cleaning is more practical since you
have to schedule them one at a time