Help! Stocking 42 gallon aquarium

[Gallonsoffish]

I have recently finished cycling my tank for 2 weeks, put in some fish. Here's the list
11 rummy nose tetras
4 sterbai cory
1 swordtail(another disappeared)
I am looking for affordable centerpiece fish, as well as top-level fish. The aquarium is mostly filled with fake plants and stone. Btw my cories just go up and down the sides of the tank all day lol Thanks in advance!

[Gallonsoffish]

Sorry, it was 50 US gallons. I am also looking for easier to keep fish, so rams and apistos are out of the question. What about killifish? By the way, I really want something that has a huge pop of colour.