Ask HN: Cloud File Synchronization Solution with Archiving Support

Currently I have a Dropbox Business Account with a team folder that my staff uses. Latley, I have been having synchronization problems: File conflicts and move operations that show up as deletions (the data is restored right afterwards). I think its related to when a new Dropbox client is setup. With dropbox you can't specify a custom location during setup and have to set that up later. During one of these setups, when dropbox moved the data from its local default location, to the local custom location, it mirrored that operation on the cloud somehow. I think I lost some data during this issue. We configured dropbox for the whole team to online-only and that seem to fix the problem, but now I am worried about backup. I'm starting to think that my dropbox team folder is getting too big and its causing issues with syncing. So I have been thinking about an archive solution where I would only store a few years worth of data on the team folder and then archive the rest off-site. The problem is that I dont know the best solution for this situation. I run a small business with 5 employees. Most of the solutions out there that address my problem are for organizations way larger than mine. Does anyone have any experience with an issue like this that could point me in the right direction? I'd rather not setup a computer to perform this operation on my end and am looking for some kind of cloud solution, or a client that can run along side my dropbox client that I could manage independently of the dropbox online-only configuration. Or maybe I should be looking at a different cloud solution?