IDK where you are but the only vendors I would trust to do that are in Austin Texas and Atlanta Georgia.
I lived in West Lafayette Indiana for a couple years. The deep well water there is rock hard, good for African cichlid. All your Africans shown are Mbuna, and the most aggressive species except for the yellow Lab. They are cute at 1 to 2 inch, and as they reach 4 to 6 inch, even a 75 gal won't be able to stop the killing field. It's a domino effect. As the population thins out by murder, the aggression will target on fewer victims and eventually, you will be lucky to have 2 to 3 fish left. At that size, you can't add new fish without immediate termination. Mbuna are disproportionally aggressive relative to their small size. I don't think you can maintain a harmonious Mbuna tank less than 125 with lot of rock work. You are not alone. Most people first experience with Africans was Mbuna because they are cheap, colorful and cute little munchkins. If they stay with Africans, they will likely and naturally move into more tolerant Peacock, Haplochromine and Tanganyikan species.
Your selection works, because you have the smallest and most peaceful Mbuna except for the Afra, and you have only 4 males. If you have one Kenya, one zebra, or one Auratus male that can grow to 6 inch psycho, you are waiting for eventual mass murder. Also, preselecting the sex ratio of Mbuna in your case won't be possible until the fish start breeding, meaning that you are relying on natural culling to eliminate extra males.I find mbuna easy to keep and have had a tank or tanks of them for more than 10 years. It is just a question of matching the fish to the tank size and their tank mates.
For a 75G this would be a very nice tank with no killers:
1m:4f Labidochromis caeruleus (yellow labs)
1m:4f Iodotropheus sprengerae (rusties)
1m:4f Pseudotropheus acei
1m:4f Cynotillapia zebroides (a.k.a. afra) Cobue