I have occasionally used a piece of overhead projector plastic to help dissapate excess current in a Penguin 350 (and the like). SInce then I have discovered the the plastic covers that they sell for report covers at the office supply work even better, for they are a little thicker and have rounded corners already, so I do not have to trim them.
I take the piece of plastic and lay it over the side of the tank, so a portion is extending out across the surface of the water. The filter is placed on top of the plastic, over the side of the tank. The filter will hold the plastic in place by sitting on it.
The water is discharged from the filter, but, instead of falling straight down into the tank, it runs across the surface of the plastic and spreads out, losing momentum before it goes into the tank. YOu may have to diddle with it a bit to get the right amount of plastic on the surface to balance the flow of the filter, but once set up, it can remain for as long as needed. This will help a lot with excess currents. Your little guys will grow quickly and soon not need any help, though.
I also think that if you place a set of plants (plastic or real), and/or stones in a concentrated area of the tank, they will break up the current sufficiantly that the fish will have a place of little current where they can comfortably sleep. As long as you have provided this "sweet spot" for them, they may enjoy riding the currents and bouncing around. When they are tired, they can seek the quiet area.
Your little guys sound so cute. I love little fishies - the babies grow so quickly, do they not?