I only skimmed the thread... I know of people who trained their ribbons to eat by feeding fire fish first. They'll eat the small fish.
And Tank, if you want to keep your clowns in the display tank, stay away from the stout and fimbriated. You might have luck with the miliaris, but your best bet is a dwarf or zebra eel. For what it's worth, I kept a pair of perculas with a dwarf and miliaris for two years without issue. One day I didn't feed the miliaris to satiation and my male clown disappeared. Don't know if it was definitely the eel as there are other suspects, but it's something to be aware of. The miliaris ate fairy wrasses, though, I know that. You said earlier you intended to keep only a few larger fish with the eel, but if you want to keep smaller clowns, I'd recommend the dwarf or zebra. The zebra gets large, so it'll limit your other stocking options.