Most of the upper jaws except a teugelsi, weeksii or ornate would be fine in a 90g. Depends on the dimensions but these three to avoid with smaller tanks.
Would suggest Senegalus, delhezi, retropinnis, palmas polli, palmas palmas and buttekoferi.
Here’s a good link with info. Size can be 12-14in and a bit more for other species.
https://www.monsterfishkeepers.com/forums/threads/all-bichir-polypterus-species-updated.684410/
Not specific water parameters, not fussy eaters, need clean water like other fish, and need open parts of the tank to be covered. Would avoid small fish. If it can fit in it’s mout then it can become a meal. Fish wider than their mouths will work but nothing too aggressive.