I am trying to setup a proxy server for a few members of my team. I want to give it to them through my VPS server, what I want to know is I want to give at least 30 IPs from different country then next 30 from another country and so one.What I am not clear with is from where can I get IPs and in this case what should be my approach to setup the server.Since I have only have experienced with squid as a proxy on linux and in that I just had to give my server IP and NAT the connection but in this case I myself want my users to have some IP which should be different than mine.
IPv4 addresses are a very rare commodity. Getting multiple blocks of 30 IPs will be next to impossible (and/or very very expensive). You will probably have to look into TOR, which is slow and can cause security issues, but will allow you to make outgoing TCP connections from around 3000+ IPs around the world. You can select the exit node manually; consult the TOR manual for more information.