A couple of years back I found a place out of oregon that was selling rhea feathers for a very good price. I bought a crap ton and still have half of a crap ton. Happy to send you a few feathers if you would like to give some a go.

Lady Amherst is another nice addition, though it adds a bit of contrast+color, I don't think it does much for the action of the fly, thus I have been leaving it out more that putting it in lately. Guinea feathers under the rhea and ostrich.