I'm building a site that I plan to grow to the size of SO. I'm only planning to have one prodcuction server to start off with. This will host everything including the database. I know it's very hard to say but am I likely to run into trouble quickly (if the site takes off) and if this is the case should I start out with more than one server so I can load balance everything from day 1? If no, should I be looking for something a little bigger than this spec?: http://www.123-reg.co.uk/dedicated-server-hosting/