The bigger the footprint, the better, as your tank is on the hairy edge of too small.
The coldwater cat sharks, such as chain, izu, and cloudy are all available as captive bred speciemens, but require a temp in the 50*F - 60*F range. There are tropical species (coral, marbled, and Bali), but they get larger. FWIW, the brown-banded carpet shark (the most commonly-offered shark) is often mis-ID'd as a cat shark, but get too large for most home tanks, so know your shark species.
The Papua New Guinea Epaulette is a good one...they're very hardy, and fairly tolerant of low oxygen and temporary water swings. I've heard they can even live short periods out of water. The PNG is a "walking" shark that can navigate spaces between the rockwork. I think they look nice too.
That's pushing the envelope about what I know about elasmobranchs as I've never kept them, but being a "pred guy", one learns a few things...
HTH