Sorry you have to rehome your fish. They are *superb* animals, though not for everyone. I hope someone manages to provide you Panaque a nice home.
I will mention that I've had some success keeping a somewhat larger specimen in a planted aquarium. The "trick" is to create a terrain with a definite low point at the front. The wood chippings collect there, and can be easily siphoned out. every few days.
It's also worth mentioning that while unsightly, these chippings have no effect on water quality.
At the moment the tank has one half at the back filled with water lilies of some kind plus a few other one-off plants (Cryptocorynes for example) that are flexible enough not to be damaged by the Panaque as she swims about. The gravel bed at the front half of the tank is a couple of inches lower than the back. The two halves are separated with bogwood, used to "shore up" the cliff between them. Underneath the top inch or so of sand + gravel is a plastic gravel tidy (actually, just some plastic mesh bought cheaply from a garden centre). Under that is the gravel + soil mix for the plants to root in. The plastic mesh prevents the catfish from digging disruptively. The plants quickly secure themselves onto the mesh with their roots, making it difficult for her to uproot them.
So far, everything seems to be working well, and the tank isn't as messy as you might think.
Cheers, Neale