I am looking to set up a small network for a client which would be isolated from his primary network. (I'm hoping to set-up the additional network as VMs on the primary network.)

I've instructed the client to request a bunch of static ip addresses from his ISP, but I'm not sure how to proceed with setting this up.

What hardware will I need and how do I go about the configuration?

Heavy security is not my concern. All that's really required is that web requests from the two networks be presented to the outside world with different ip addresses.