When I see an 'English Biotope' I picture a top hat and a monocle on that fish
I googled '55 gal Lake Malawi tank' and got a thread from another forum with someone attempting one, their suggestions were;
Electric Yellow lab (Labidochromis caeruleus)
Among others, I'm cross referencing from the list with what my local lfs sells and so far the Lab is the only commonality.
Some others that the LFS lists but the forum I found are;
Jewel Cichlids
Kenyi Cichlids
Bumblebee Cichlid ect
(I don't recall seeing said fish at the store, but apparently they get them sometimes

) My local LFS doesn't stock very much
I have no idea what a good stock would be if I went the Lake Malawi route, as no matter how lovely the list is, it all depends on if I can get said fish, but any suggestions that I should keep an eye out for and do research on?