I have a bunch of winged Seraphim. Most are actual Seraphim with wings. I did convert a Celestine out of a Ghost from Reaper, using eagle wings and such. Most I did used hawkrider wings, but I have also sculpted a lot of my own wings. I struggled to find wings I liked and could shape. Anyway, Link to my gallery here:
https://www.dakkadakka.com/gallery/images-102599-51533_Sister%27s%20Of%20Battle.html
As well as my regular page where there are more pictures:
http://edwardmystcreations.weebly.com/sisters-seraphim.html
I wish I had some suggestions for alternate miniatures that are less expensive. I don't. Sculpting wings is time consuming, but really not very hard. If you really care, I gave some pointers here:
https://www.dakkadakka.com/dakkaforum/posts/list/731293.page
I sculpt a lot, I do not claim to be an expert.