You should apply the service pack immediately after you finish the Win2K installation regardless what you install aftwards. Then you should go to windowsupdate.microsoft.com to download the latest patches. As for Oracle for NT- you can install it on any version of NT (NT workstation/server, 2000 workstation/server) so those questions shouldn't affect Oracle at all. I mean you can have none of the server services like IIS, FTP, etc running and still install Oracle successfully. A hint on the configuration though- if the server is to serve a lot of users, then select the app/db or file server option. If you are just evaluating it you should select the option where the foreground applications have more priority than the background services.
David