Do you really need more then 1 IP address? Why not setup a router that supports NAT (as your friend suggested) and then host all of the websites on an internal LAN. Then setup different DMZs (Demilitarized Zones A.K.A port forwarding) to forward connections to your servers. Used in combination with domain names, this system could be deployed transparently.

I'm not sure what your friend means by using a VPN to tunnel traffic to your router... That part didn't make much sense to me. As far as I know, it would be impossible to use IP addresses from other ISPs, because it would make routing impossible.

--Sudo