I like cory's..didnt know pictus cats could be in groups.I always thought that they were territorial. what is a good big single cat that could go with a severum.?
My pictus cats stayed together in my 55 but once they got into our 150gal tank they sort of staked out their territory but they've never been aggressive to defend it.
You could try a sun catfish (eclipse catfish). If you get it at a small size it will grow slowly. You will probably have to upgrade a couple years down the road ours has only grown an inch or two in a year. It will get big eventually though. They hide most of the time though. You have to sort of know where their hiding spot is if you want to try and find it during the day. At night our guys is out and about hunting for food constantly. He eats at feeding time, of course, but only peeks out from the safety of his rocky hiding spot.