Welcome to AC, Fishtankearl82
I agree with what every here has posted about tiger barbs. If anything they would just cause problems. Not very model citizens. They also occupy the same area of the water column that rainbows do and with their personalities they would get in the bows faces.
I agree also, about the gouramis. I've had bad experiences mixing blue "three spot" gouramis and rainbows. Two of my females got into a row and the blue gourami decided to join them. He tore one of my females up pretty badly and I lost her to fungus. I won't put anything but maybe one dwarf gourami in with my fish.
As for recommendations, I would add in a few more Boesemani. Go at least 8 of them. Try, if you can, to keep it two females to every male, or at bare minimum, one female per male.
Clowns. Clown loaches. Yah! They do GREAT with bows. They don't bother each other and both chefkeith (I think his are in with his boesemanis) and nursie and I have clowns with ours. They get big and need to be in groups of three.
Corycats, kuhlii loaches -- all are fine with bows.
As for other schooling fish, what I would suggest is that you just load up with boesemani for now. See how they do. You may not *want* any other schooling fish in their way. They're pretty active. You can decide later if you want to increase the school or add different fish.
If you do decide to add others -- platys (don't school as a rule, but my male likes to school with the rainbows), rasboras, rummy nose tetras, anything like that. Althought I've had no problem with small tetras like neons or glo-lites -- I've had them with all my bows -- I've read that some people have them get eaten, so exercise caution with smaller fish.
Roan
