The above (pictured) accomplishes my goals. I can put up to 6 large Marina hang on the side breeder boxes on the 15g tank. The 15g tank offers huge buffering capacity as well as the ability to have filtration and great aeration - both from the filter and the drips into the breeder boxes. It will also allow easy water changes without disturbing the fry.
Currently I have A. garderni in the front left box from two different hatch dates with a plastic divider between them. In the front right box are A. ogoense from two different hatch dates. Due to the small size of the fry on the right I have substituted a foam divider for their safety as well as foam in front of the overflow to prevent them from being washed into the 15g tank. The box on the right contains S. santanae fry.
I have noticed a big increase in growth rates since starting this system as I can now feed them frequently and good quantities without fear of contaminating the water.