What is the best technology for a WAN project with a central server?

hi,
I would like to implement a WAN project with several servers in different locations connected to and managed by a central server. But I couldnt decide whether directing a user to a closer server or make central server a bridge for communication. Central server will welcome the user first and every node server will cary information about the place where it belongs. According to choise of the user from the central server, the information requested will be shown to the user. Because it will be a WAN application and covers a huge geographical area I need to consider and evaluate every possibilites.

Thanks for your comments and helps.