Looking on how to set up multiple sites with two devices per site using site to site vpns

Hi all

Looking on how to set up multiple sites with two devices per site using site to site vpns. I'm looking at what the network diagram would look like with that setup. Specifically having two site to site vpns per site. What would the connectivity look like? If using BGP for failover what would that configuration look like?

Many thanks for any help that anybody is able to provide,

John