What service providers are providing for Data backup

HI, I am just wondering what kind of Backup/Restore services are any service providers providing to their customers.

I am running as IT Service provider and trying to setup Private cloud for Backup.

I think I need a agent based software which I can install on client side and which will backup data to storage sitting on my personal cloud.

1. And 2nd how we can setup Private cloud, nothing fancy, just put a storage unit and make it accessible to clients for data backup and restore.

2. Any recommendations on Hardware (Storage)