Welcome to the forum first of all. Glad you found us
There are a lot of Cichlids, Lake Malawi, Lake Victoria, Lake Tanganyika, South American, Central American....
You are not going to be able to keep that many in the tank though as a lot of them get too big for your tank size.
Oscar - tank is too small. Lake Tanganyika
You can do a pair of Altolamprologus calvus , compressiceps, Neolamprologus leleupi
, , Julidochromis
or brichardi Lake Malawi
Electric Yellow Labs, Red Zebra (Metriclima Estherae), Rusty (Iodeptropheus Sprengae), Pseudotropheus Socolofi, Cynotilapia Afra, Salousi- 5 of these fish spread over 3 species...in a Male to female ratio of 1 male to 4 female to help spread aggression.
Lake Malawi Peacock Cichlids - 10-15 fish. Other cichlids
1 convict, 1 firemouth, and 1 Blood Parrot South American Cichlids Apistogramma agassizii, Apistogramma nijsseni
This list is NOT exhaustive and there are many many others.
Now onto Water Parameters.
Lake Malawi need HARD water with a pH around 7.8
Lake Tanganyika need VERY HARD water with a pH around 8.6
Central American need Hard Water around pH 7-7.6
South American need SOFT water around Neutral (pH7) Temperatures
range from 70-78F for most all the fish listed. Lighting
NOT a problem, that light is more than enough.. Filtration
depends on what fish you choose, Lake Malawi though require high flow rates and over-filtration of 10-15 times your tank volume.
Some cichlids require softer flow. Decoration
Malawi - ROCKS, ROCKS AND MORE ROCKS with a sand substrate.
But really depends on what fish you choose.
Is the tank cycled already?, as you will unlikely be able to achieve a complete cycle unless you heavily use filter media from a well established tank.
There is an awful lot for you to decide, first of all choose a geographic area and then we can offer stocking suggestions based on what you choose.
Hope this helps and as I mentioned there are an awful lot of species of cichlids and it is impossible to list them all here.