Not all africans are the same
you generally need to decide on if you are keeping lake ( and then which lake) or riverine fish
some of the riverine fish are more suited to a tank your size but so also are some of the smaller lake fish.
once you have decided that you can then look at water chemisty most of which can be dictacted by the substrate and background and filter contents.
For example instead of silca sand you may choose coral sand or a mix of both to change your water pH and hardness.
In a 90l tank you could consider such diverse fish as kribs ( many types now available here) Dwarf cichlids ( apistos are most common), lumpheads or even some of the lamp., neolamp., or julidochromis species available depending on budget.
This may mean you can even keep some of your plants
HTH
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