My stocking choices for your tank (assuming all lion tank) would be:
Radiated / Clearfin - 9-10 inches - 65g
Antennata / Spot-finned lion - 8-9 inches - 55g
Fuzzy Dwarf - 7-8 inches - 30g
This would give you a variety plus offer these lions space, Radiata & Antennata are beautiful lions, they both like Crab and Shrimp, so I think it would be easier to wean 2 lion that prefer the same type of foods.
Volitans are nice but they grow fast and reach 12 - 15 inches, the Russell's looks similar to the Volitan but again, grow fast and reach 10 - 12 inches.
Kaye