Suggested hardware config/OS?

Do you folks have any suggested hardware/os specs for something that would run with 1000-15,000 connections?

I’‘m looking more for a general resource per connection figure, and maybe just some more information about what’'s recommended in general.

Not sure about hardware, but I think you should go with a linux/mysql config. I use the built in database, but I don’'t have near that many users.