You should consider VPS mirroring solution in this case. As it is not a cheap hosting solution but if you want to offer ideal VPS set up, then you need to consider this solution as well.
You can create VPS on a main node, just like any other VPS, however, you need to create same VPS with same configuration on another node, which would act as a slave VPS. Hence, if one VPS node goes down due to any reason, then another VPS node can execute all the operation of that node without any fault.
Since you are not putting any load balancer or round robin DNS in your description, I feel you are actually placing two identical VPS on different nodes, and this will not work, talk about arp storms.