I use the two of the 820 models (that each put out 820 gph) along with a mag 9.5 sump return in my 55 and while it’s a brisk current it doesn’t seem too overwhelming even though my turnover is around 40 times per hour. The seio pumps put out a gentle flow and not the kind of powerful direct flow like the Maxi-jet pumps do.
If you have the funds a couple of
Tunze Turbelle Pumps would be even better since you could add a wave maker at a later date but they run around $150+ per unit which is why I didn’t recommend them the first time. With a controller ($300+) the current can be adjusted at random both turning the units on and off and increasing/reducing the current flow for a true reef like experience.
The seio pumps are not designed to be turned on/off all the time but with both pointed at each other I get a fairly good mix of currents along with the Mag 9.5 return in the middle pointed towards the front. You can adjust the direction on the seio pumps, the main thing you want to avoid is a circular type of pattern that moves the water in only one direction.
With them facing directly the two current streams merge together somewhat and send the current in multiple directions.