So much info depending on which way you go with the tank, so I'm going to wait and see which direction you start in.
My general suggestions would be:
Yes on the canister filter, it doesn't have to be expensive, there are some good cheap ones on Amazon. Definitely the style to go with.
LED light, yes, get one with the ability to grow plants(just in case, and the girls will love the blue "moon light" function that most have.
I'd rethink the stance on plants, some simple low maintenance plants can cut way down on algae and waste. They add a lot to a tank aesthetically.
Africans are awesome and beautiful, but limited in quantity by aggression in a 55. Choose wisely. I really like a south American tank, so many options there.
Good luck, I can't wait to set up my 125 with my girls when they are older, or go bigger, lol.
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