Question about VPN?

Hi to all TechRepublic. I want to setup a site to site VPN and im using a Broadband VPN/DSL Router endpoint in my 1st computer shop with 10 computers running winxp but im confuse about what will i do to connect my 2nd shop with a 10 computer runing winxp should I use also a vpn router? or do i have to make a server to make my 1st shop connect to my 2nd shop? what protocol is use for gaming? if its UDP how can i broadcast UDP in VPN that acts like a LAN? what is the best method use for VPN Hardware based or Software based? i have a little back ground on setting up VPN but only for Remote Connection ive never setup a site to site before pls help me thank you for the reply.