Many to many NAT device

I have multiple router to router VPN connections setup with my company and our customers. I am now coming across a problem where 2 customer subnets are conflict (both using 10.1.x.x). I think my solution will be to use many to many NAT, but I am not finding devices that will do this and nothing else.

I am pretty sure that my choices are Sonicwall, cisco(linksys), netgear or juniper.

Any thoughts?