Newbie: Converting Turtle tank into Cichlid tank

[Evil_Jon]

Hello-

I have a 120G tank that I kept snapping turtles in until recently. I don't really know anything about fish keeping aside from a few feeder fish that managed to survive but I want to convert it to a cichlid tank.

For equipment I have a 24x24x48 120G tank, 2 Rena XP2 canister filters, a submersible heater, & some air stones.

Is this all I need to get started?

Is a protein skimmer for sw tanks only? I hate cleaning.

I see a lot of talk about sumps, should I set one up or are my canister filters adequate?

Thanks -
Evil Jon