Dither fish for baby severums

Some of the tetras can be a bit nippy. Your severum should grow fairly quickly. I had mine in with some other fish when they were small, but can't really remember what. Mine liked to be able to "sort of hide", but be able to interact on their terms. If you have some kind of rock arrangement, or something of that sort, he may hide behind it when you come in the room, but if you sit by the tank, he'll probably play "peek-a-boo" with you, then come check you out. They can be characters. Also quite territorial. Mine are the "police" of the tank. Anything new, whether fish or rock, has to pass their inspection.

I've found that Tin Foil barbs are good dither fish. Their movements are a bit quirky but they do swim and bring out my other fish.

a school of silver dollars

In a 35g tank, you won't have much room for tinfoil barbs or silver dollars...they get too large. Giant danios are smaller, but large enough to handle even a full-grown severum, at least in my opinion. Any of the rainbow species (except for the pygmy) would also be large enough, although much pricier.