SOunds like you are looking for a Media Server, storage being a secondary issue.
www.avsforum.com is a great place for info like this.
there are some wireless routers that have built-in media servers
You can use a PS3 for this as well. And there is a Xtreamer Pro box that is an all in one solution. I would like to hear about more all-in-one solutions if you come across any.