Debating the best "community" bichir tank...

So I finally picked up a polypterus senegalus after wanting one for a very long time, (picking up a 2nd one later in the week) and trying to decide on what other fish to keep with them. Contemplating something along the lines of a couple silver dollars, or even maybe an oscar (sized appropriately to avoid the bichirs becoming food). They will be in a 75 gallon with sump filtration. I'd appreciate input from anyone who has some insight that they could share regarding polys and community tanks. The polys are currently rather small (in the 3" range) so have a while before the community tank setup will be put into use.