I've heard a lot of talk about ZabaSearch. It searches publicly able government records as well as some commercial sources. A lot of people say that it violates their privacy because it's so easy to find people, so I guess it works pretty good.
WPA is, I believe, currently the strongest. For encryption, TKIP is probably the most supported algorithm, but if your gear does AES, I'd use that. You've got two main options for authentication sources.