What Server do I need?

It's rare these days to set up your own server as a web-host, unless you are a large corporate: the bandwidth available on a "domestic" connection is generally a bit too low - though that is changing, you have to remember that the serving of the webpages generates a lot more traffic than the user request, and that would be coming from your "upload" bandwidth not "download" which is generally 1/10 the connection speed.

Talk to your chosen hosting service - you'll likely find that unless you specify (and pay for!) a dedicated server you don't get a lot of choice in this. Most hosting services use a server farm, and allocate incoming users to a "next free" server to run your website app - so the load balancing is down to them. They will be able to suggest a suitable package based your your traffic estimates.