Firstly, you seem to be confusing VPS with VPN. VPN to me means Virtual Private Network, which makes your post make fuckall sense, whereas VPS means Virtual Private Server.
The difference between a dedicated server, and a virtual private server, is that the dedicated server will be a physical machine which you have sole usage over, and a VPS is a physical machine with several virtual machines run on it - which could be shared with n number of people though you will have guaranteed resources (ram/cpu/hdd/connection speed) which you do not get from shared hosting. VPS is the step up from shared hosting without the cost of going Dedicated.
What you need is an offsite backup facility. As such I would recommend neither VPS or Dedicated, instead I would use something like Amazon's S3?
Amazon.com: Amazon S3, Amazon Simple Storage Service, Unlimited Online Storage: Amazon Web Services