So I am doing some testing at the moment, potentially looking at using a VPN solution in the states or something.

I have been able to so far work out that I need to route x.x.x.x/xx to the gateway of the VPN tunnel, but this is an IP address. While this works, it's not ideal if you have a VPN that has a different gateway address each time (or if you move to a different VPN).

Is there anyway with the static routing option, or using iptables (probably one in the same), to route x.x.x.x/xx to an interface rather than a gateway IP on an interface?

How is everyone working with these types of services anyway? do they have a somewhat static gateway address?