My tank is stocked with
1x JD
1xKirin Parrot
1xBlood parrot
1xseverum
1x Female convict
3x EB Acara
2x peacock eels
1x synodontis
Very overstocked for my 55/65 gallons (good thing they're still small), but I keep up with water water changes 3x a week so it helps.
I hope this can sorta give you an idea just as long as you don't overstock it.
If I were to get a 90 gallon I would stock it with
3-5x Acaras
1x JD
1x severum
And maybe like 2x female convicts as they stay smaller than males.
And maybe some other bottom dwellers