Ask HN: Is simple file sync/bkup for a small distributed team solved yet?

I have a very small company and we all work from home. I am trying to setup a seamless backup solution for all of our machines.

I am going to use Dropbox Pro to sync all of our important stuff, but we have large media files that we need backed up.

I want to get a dedicated server in my home office and setup a network share (over the internet) where they can just drop large media files in that folder/network share and it automatically gets uploaded to my server.

Then I would like to backup that server to some remote service.

My partners have Macs, I have both a Mac and a PC.

Is there a simple system/solution that will allow me to do all of the above seamlessly?

I am very technical, but I am looking for the simplest solution to both setup and work.