I would aim to get 6 more cichlids around 2-3", try to get ones that don't look too similar, and let them grow up together. You will probably have to tweak the stock as the fish grow until you find a good mix, but growing them out together will get them used to being in a community. Keep in mind the fish you have are quick growers, so you will want some that will grow at a similar pace, or if they are slow growers, get them a little bit larger.
Some species to look at would be:
Parachromis loisellei
H carpintis
N tetracanthus
A. lyonsi
V. breidohri
Salvini