If you can take advantage of the petco $1 sale, or not, a 20L is a great size for your tanks. Also depends on how much space you have under the tank and what you want to put in the sump. Chaeto, refugium, frag tank, mantis sanctuary. As far as baffles got, a glass shop can cut them for you for about $10 a pop. Glass and be siliconed to glass, but glass and acrylic don't silicone well. It more wedged in than glued in.