There is such an endless amount of possibilities when you have a clean tank and are open to what goes in it! Lol
Even now as I'm thinking about what you could do, there is just too many species and set ups to choose from to give advice. I know what I would do, but I know what I like. I keep mainly Malawi cichlids, I have 2 species of tanganyika cichlid, and 3 species of south American cichlid. For me I like the size , and colour variations, they are there own characters and show interesting behaviour especially when breeding.
Although if you what live plants avoid Malawi cichlids, as they will eat or dig them up.
Let's us know how you get on. Once you know what sort of road you want to go down more advice will be available.