Offering suggested images for user cover image

I’d like to offer my site’s users four or five pre-selected options for their cover image, as well as the ability to upload their own.

I found the UnSplash extension, that allows them to choose photos from a remote (and I assume, paid) service. I would like to do something similar, but with images we own/control.

Has anyone seen an extension that would do something like this?

For context, I am only likely to have 40 – 50 site members at any one time (all employees).

Thanks, folks!

–don