I've found that the less decoration in a pacman's tank the better. I know some people recommend hides, but mine is perfectly content to just burrow in dirt. I used to have a hide in his tank, but he just ignored it for three weeks, and it was taking up a lot of space, so it's not there anymore. He does have a fake aquarium plant in there, but that's more because I wanted some greenery than because he really seems to like it. Mainly, as long as they have a water bowl and dirt, they'll be happy.
Just a heads up for when you're deciding on species: Petco and Petsmart have a tendency to sell Cranwellis as Ornatas while they're still babies. I personally don't mind that I have a cranwelli, but if you really want the bright ornate colors be really careful picking out your frog
