SQL server Solution on 2K

Hi. I am about implement an online DB solution for my company and wondered if anyone could share their experience with me. I am co-locating the hardware for this in a London server house where the backend DB is SQL server and users can access it thru IE5. Is it better to purchase 2 Servers (1x SQL-1x Web), 2 copies of Win2K, and a single processor license for SQL or could I get away with a single server(Dell PE 2650, dual 3GB Xeon, 2GB RAM) with SQL server and WIN2K installed. I am unsure if its a good idea to have both web server & SQL on same machine but cannot find anyone to tell either way. The database is accessed by password login but there will be a firewall in the rack to keep out any unwanted “Guests!”..I realise this is a basic explanation, but hope you can assist..
Thanx for your time
G