What Type Of Tank Do You Think?

[bball4life]

Hey all, I have an empty 25 gallon tank that I dont know what to do with. I wanted to do a gravel change before I do anything and I might change it to sand, but I am not sure. I either wanted a community tank or a school of maybe smaller fish. What type should I do, and what breed of fish?
Thank you

 

[Dorkhedeos]

cardinal tetras, corys, khulis