I quite like the idea of a lot of apistos, although the mix of colour might be a bit messy.
I like frontosia quite a lot too.
Personally I don't like africans that much, and although you might be able to fit a lot of africans in that tank, too many might make the tank end up looking smaller. Angels would be nice. Proper angels, not the cheap looking kois and marbled ones
With a large tank like that, you have heaps of options and also potential for a LOT of hiding spaces - which means more territories etc.
You could get large plecos which not too many people have because of space needed.
Arowana.
Larger agressive SA cichlids.
(I'm already thinking about how I would scape that tank :oops: )
I shall stop now.