I feel your loss! I had a home burn down in 2015 and lost everything. Including a 7 year old Argentinean Tegu, several young Ball Pythons (the early stage of an attempted breeding program, all fancy morphs) and a 125 Gal aquarium with my prized Cichlids after already greatly reducing my fish stock. I wish you the best in rebuilding your life, your necessities and when appropriate your fish collection.
There are a few Dwarf Cichlids that would be very comfortable in that aquarium. There are quite a few species within Apistogramma. Most do well in small breeding groups with 1 male and any number of females. I have tried more than 1 male in groups several times, but only successfully in larger tanks. There is also a Dwarf Cichlid called Rams (Mikrogeophagus ramirezi) that would do well, though they do best in male/female pairs, not groups.
Either option would primarily stay at the bottom of the tank. This leaves your upper levels open for something else. You could go with Angel fish, which I don't know much about. Or a bunch of smaller community fish.
After my fire I was in a similar situation for a few years and kept a single 40 breeder. I kept 2 male Apistos (no females) and a group of Endlers. I had several house plants (Pothos & Black Pagoda) that dropped into the tank. Using plants and rocks I set up several areas with a lot of crevices and caves the fish couldn't get into then added Cherry Shrimp. It was a fun little tank that scratched my fish itch. Then when I got more critical things in place I was able to start re-growing my aquatic hobby and just last week ordered several huge aquariums.
Take the time you need to rebuild. You'll get there. And make the most out of your smaller aquarium until you do.
