Cobbles form a brook or in woods etc work well. Yeah most likely the fish would need mail ordering from somewhere. I see you in N Ireland. Im sure there maybe a cichlid forum there that may sell them. I dont know if you have an aquarist classified there either.
Black background is good. Coral sand for the bottom. this will buffer the water a bit but your ph is ok anyway. Cheaper option would be any kiln dried sand from a builders merchants. The rocks that you will get will end up growing algae on anyway so a natural stone- slate cobbles will go green and make it more natural looking. What ever you prefer really.
Regarding the cyprichomois utinta, if you cant find them, cyp mpulunga are similar aswell. There both the smaller type of cyp that you want.
