I don't think static nat would be necessary. What a static nat does is translates a public address to a private address.
The only thing you need to connect to the inet is a public ip. I would think that you could do the following:
connect the modem to the wan port of a soho router.
setup a soho router with a public ip.
connect a pc to a switch port on the router.
configure the pc with a different public ip than the router.
set the default gateway to the ip of the router.
ping default gateway.
ping internet.