Some friends and I are working on a medley chorus using only UTAU that are discontinued/abandoned with no more public download links.
Here is our current list:
https://docs.google.com/document/d/1WX8SOI_56-nw89HSen3ExdMf1dtF1z4pWlKNz-K3K-U/edit
We have access to most of these voicebanks...