Hi and welcome to the forum!
For your 90 gallon here's some suggestions:
1 Oscar (fake plants with these guys. Mine likes to drag his fake plant around)
Or
2 severum (yes, they'll munch on plants)
5-6 cories
6 larger bodied tetra such as Diamond tetra or Columbian tetras
Or
A pair of green terrors
Or
A pair of Jack Dempseys
It's hit or miss on adding some smaller tankmates with the green terrors and JDs if you do pairs. You might be able to get away with a Firemouth or convict or something like a Raphael catfish. The Oscar you might be able to add one other fish along that same line but you'll need to be diligent on weekly water changes.
Another nice cichlid for that size tank are salvini. Beautiful fish but aggressive and can tend to be shy but not always.
Texas cichlid is another possibility. Again hit or miss on keeping any tankmates with it in that size tank.