Dithers for Rays

Ok so right now I'm growing out a male Motoro as well as a female Reticulated. Motoro is probably 7-8"disk and the reticulated is probably at 5-6"disk. Currently as dithers I have 4 Tinfoil Barbs and 8 Filament Barbs. They're extremely active, don't bother my rays whatsoever and add movement that the tank needs, mostly to keep everyone else in the house off my back. However, during feeding time is gets to be a mission to feed the rays. I'm hand feeding the both of them and the rays have come to understand that the second my hand hits the water they must haul *** to wherever I'm at before any of the barbs notice and swarm me to get their food. As much as I like the barbs, I'd like some suggestions on some potential dithers that are more or less as active as them but not as daring as to try to rip the shrimp/bloodworms from my hand. Any ideas?

I love Red Hooks but they're hard to come by for a decent price around me. And I don't really like the regular species of dollar. The Black Skirt Tetras are a good idea, but the rays have other tank mates that may make that difficult. They're in with a 6" Black Arowana that I'm also growing out as well as a 9" Senegal Bichir. I can only see those tetras becoming lunch for one of those two.

I've never really been a fan of the geophagus, but I am intrigued by the idea of some severums. Do you guys think maybe 4 or 5 will be good enough to replace my barbs?