Need to build a virtual community

Hi all, I need to build a virtual community like "Second Life" but small size and linked with real life services. Basically it will be a virtual place where ppl may shopping, play on casino, chat with other members, contract services, etc. The primary idea was to have the structure of a castle with all the services inside, but we are open to ideas regarding a different place than a castle. Basically ppl will be able to register, the user will need to create an avatar to interact on this virtual community, but the Avatar should look like the user is on real life (not sure how to implement this, so we are open to ideas as well), ability to e-commerce and user will be able to manage their own account but not to change their names. This is more than a website it is a virtual community.