External media library hosting?

Do you have a recommended solution for external media library hosting? I’m needing a total off load of media to an as yet, undetermined, external host, not just for performance purposes.

I am migrating a legacy app to a self hosted wordpress site using your theme. I have approx 25,000 plus images and approx 48,000 listings to import.
I am hosting the Word Press site with a Digital Ocean droplet but there is no way I am going to allow 25,000+ images to exist in the same server.

So I need an external host with HTTPS support for the media library as this will take care of future image hosting for my customers, as well as for the initial import.

At this time I haven’t chosen the external host. I am looking at DropBox, Amazon S3, Flickr to name a few but before I choose I need to prove the concept.

To achieve this I have looked at various CDN solutions for Word Press but none seem appropriate as most seem to either

1) “mirror” the media library resulting in images still existing on the main server or

2) Want to transfer the whole domain by taking over the DNS records which is also totally not what I want.

After extensive researching I found the w3 Total Cache plugin seems to have the functionality I need, allowing me to set FTP credentials and host details, it looks like it allows me to totally offload all my media to an external host in a flexible way but after further research it seems that the w3 total cache plugin has clashes with your booster plugin which we are using to great effect.

So, I need to know if you can recommend a plugin or a way to change word press to store and load media library content that is compatible with GeoDirectory?