I kept tropicals for many years. The 100 gallon housed a school of 13 panda cory cats and they even spawned in there. I got 5 tiny little mini replicas of the parents, they were too cute. I found the pandas would go into spawning mode after the tank was cleaned and they loved current. I also kept 3 female bettas and 1 male in that tank. It had loads of plants in there and the bettas thrived. They too spawned, and I managed to save 2 females and a male from that spawning.
Keeping the bettas and corys in a community tank can be done but the cats need a school and the bettas need cover and fairly docile tank mates.
I kept fancy guppies and mollies in that tank with them. The betta would take exception to the long fins on the sailfin mollies and be a tad aggressive towards them.
Neons or cardinal tetras would work well, again I had a school of over 20 of them in there.
Fed them all frozen bloodworms as one of their meals every day. The bettas just loved it.