Compatibility Of African Species

[TallTree01]

Hey guys, I'm planning a tank of around 180 liters, 90 x 40 x 50 cm and I've been looking into an African style tank.
Will this stocking be ok in a tank this size both bioload and compatibility wise?
8-10 upside down catfish, syno nigriventris
4-6 African butterfly cichlid, A thomasi
1 African butterfly fish pantodon buchholzi

Also, would sand or gravel be better for these guys and what should the layout of the tank look like?
Would I add them all at once once the tank has cycled, in species groups or several at a time?

 

[CSnyder00]

Use sand. And I would cut the number of catfish. That's a lot of unecessary load on the tank. Go with 6 butterfly and maybe 4-6 cats.