thanks for the input, all.
went and got fish today.
7 pygmy cory (Corydoras pygmaeus),
5 celestial pearl danios (Danio margaritatus),
3 Clown/Rocket killifish (Pseudepiplatys annulatus).
did a drip acclimation, and then dumped them in the tank. first hour or so, some of the critters seemed out of sorts, some seemed to be pretty well adjusted. now(about 2-3 hours after adding to the tank) most seem to be doing about what's expected: swimming in the current, hanging out, chasing food (the tank had a plethora of daphnia, copepods, bloodworms, nematodes, etc. during the cycling process), and looking generally happy/healthy.
I am thinking I should probably add more CPDs, and maybe a couple more pygmy cories (although, they seem to like chilling with the CPDs now and then), but I don't want to overstock/crowd my tank. (20XH: ~20"wide, ~10"deep, ~24" tall). have a fair bit of plants, but they are still getting established/growing in.
I've attached a pic (crappy cell-phone type) of the tank after adding the new critters.
I'd appreciate any advice/reccomendations as to stocking levels/etc. I'd like to try and get near that magic balance of having enough individuals to provide security/etc. to shoaling types, but not overcrowd a pretty small tank.