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Nope you are not exactly on a right track this tank is the best for a snake, being it low and large... Absolute no for pacman, way way too big. Check this care sheet Frog Forum - Pacman and Horned Frogs - Ceratophrys - Care and Breeding and if course feel free to ask as many questions as you possibly can.
this tank might work for adult pixie. Saying might because he will probably get upset with ceiling too low. Mine did and ended up with nose rub and i have 18" height. They can really jump.

Live plants wont work for either, adult pixie or pacman will crush them in no time and if not then plants will die in the amount of waste these guys produce.