You dont really need to spring for the big pumps. The main rule I try to follow is to make sure U have 2 pumps per tub, bucket or what ever. That way if one of them quits you always have a backup. Dont get me wrong more air the better but to me 2 20 dollar pumps is better than one 40 dollar pump.
Think about this to. Add a small submersible pump and place it in the corner of the tub.Aimed to the corner directly in front of it.THis will keep ur nutrients off the bottom of the tub as well as distribute the nutes and air around the root clusters. Kinda like a whirl pool effect.
Plus the Pumps make it easy for water changes by hooking up a hose and running directly to an out.