1 or 2 nic adapters on sbs 2003

is setup of sbs 2003 easier with 2 adapters or can i get away with 1 if im not looking to access the server locally other than admin on the server.
im planning to run it but access will be via vpn for a friend and staff in another location or when mobile.
Also is a separate modem and router advised rather than a asdl modem with built in router.?

so out of my depth!!!!

cheers sean