Making ESS available to WWW

We are planning on making our ESS/MSS application available to the outside world. Previously it has only been available on our intranet behind our firewall. We currently have the IIS web server, Websphere, SQL  and Lawson all on the same Windows 2003 server. I’m thinking we need to move IIS to the DMZ as a bare minimum. I'm not sure if we will want access to the applications by portal users as they have access via vpn already. Any suggestions appreciated.