Setting up meraki failover and point to point

I need some help. I will try and explain this best I can feel free to ask any questions. Let me start by saying this setup it’s screwed up cause the clients server was supposed to be housed at our data center but they pulled last minute and said they wanted it housed at one of their locations.

Equipment we have: (will update with models once I hear back from boss what they are) 2: meraki 24 port switches:MS250-24 1: meraki 8 port switch: MS220-8 3: Meraki MX firewalls: MX64

Locations: Datacenter which houses two point to point fiber connections to two remote locations (the two remote sites do not have a direct fiber connection to each other)(client site a and client site b) Client site A houses all of the servers

Goal: send all traffic over the point to point fiber connection through the data center, one one of the points fail then a second isp connection kicks in and uses a site to site vpn to keep the sites talking to each other.

For example: Site B wants to hit a server that would feed through the data center and out of that to site A. Site B wants Internet it will go out to data center then to internet.

Both sites have their own dedicated subnets. Client does not want a vpn to dictate traffic due to added latency with encryption (only the failover will use vpn)

I may be forgetting something and will update this as suggestions come in if they remind me why something won’t work.

Any help at all is much appreciated.