All the plants will be anchored to driftwood (low light plants: java fern, anubias, etc), so I'm not overly concerned with diggers. The puffer is a fahaka. He has been with a breeding pair of convicts for the past couple of years, but I've read that cons can go crazy on live plants.
Also liking the idea of the Nicaraguensis.
Thanks for the suggestions everyone. Keep 'em coming please.