Oh then go for the bala lol. And oh I'm way off lol, hope he's doing ok..The flagtails can be very aggressive toward tankmates. Mine hated silver dollars with a vengence. Ive heard they can be some nasty slime suckers.
As for balas, Ive talked with a few who have had them solo and had no issues and mine worked out great by itself until the lower jaws came into the picture and it became food.
As to the Dabola, mine has always benn with the others,it was J jaws7777 who had to separate his out.