Very expensive option for home, all servers will act as FTP/HTTP servers, you can even get XP to run nicely as a server ...if you want it even cheaper (and more secure) try linux and apache fro web services and one one the many FTP server available.
Make sure that you configure whatever you buy, properly or you can be in for a shock if someone finds your IP and it's a host ... windows isn't the best at security on a good day.
Have a read on the web about creating "honey pots" and security before putting a server on-line.
Mark