Texas holey rock is great- good for the ph, and good for caves, but it gets expensive. Get that if you can afford if.
As for fish - I'd go for a mbuna/Victorian mix tank. You can get the yellows (like yellow labs) orange( like labeotropheus trewavasae Chiluba) and blues (like demasoni) from the mbuna - but for the true red, you'd want to add some victorians (like a ruby green, Fulu or nyerei).
This way you can hv a large number of small (about 5 or 6 inches) colorful fish. These fish are just some suggestions off the top of my head - there are a ton of other options within these lakes/species. I just saw a hyjomalandi that knocked my socks off.
That's what I'd go with to get a lot of smaller colorful fish for a show tank.
Mnbuna's are lovely and colourful and work really well with lots of dockworker and work best in a well stocked tank to reduce aggression they can be a beautiful show tank
Thanks for your replies, I'm still debating between Africans or central/south Americans but if I do stock it with Africans I'm gunna go with mbuna and Victorian
Honestly you can pick and choose the fish you want. The least aggressive dont do well in mix tanks but a lot of them do however. I have tang, vics and malawi all in one tank. They do have different water parameters but most of the fish you will get here in the states is going to be used to straight tap water. They work well for me and seem happy. My Tropheus Red MOLIRO runs the house except for the Fossochromis. Even my 5inch Ruby red will cock off to the 12inch fish. Pretty awesome. I hate mbuna, they are the most aggressive and will fight fish to the death.