Since the WCF Service is exactly the same, just running on different servers, then from your client project simply add a service reference to one of them (WS1 for example). This will generate the client proxy for you. Perhaps give it a generic name too, like "serviceX" (replacing X with something appropriate for your application).
Then, in your client config file, copy the client endpoint it created and add another endpoint with the only difference being the address and the endpoint name. Maybe you want to set the endpoint name property on each endpoint to be "WS1" and "WS2" respectively.
Then, in your code, you should be able to do something like this:
(...)
serviceXClient aux = null;
if (someCondition == true)
{
aux = new serviceXClient("WS1");
}
else
{
aux = new serviceXClient("WS2");
}
aux.service(parameter1);
(...)