John this is so NEAT!!! How do you go about making something like this, even? I can't wait to see it in a planted tank, it's going to be something different, that's for sure!
You know I have soft water, so I'm not really going to be much help with stocking. . . hmmm. . .
have you considered rainbow fish? Or some glass cats would be really cool in a tank like this! Barbs, Dannio, Killifish. . . and of course live-bearers are always an option for a tank with harder-water. . . but I KNOW you really want that Puffer tank - have for some time, right?
Keep us posted, please? I really am excited to see what you do with this one!!!