Sorry that was a bit harsh, but I've experienced in the past that people were seeking only profit out of some "help" pages filled with useful keywords.
Gentoo is a version independent distro. The Version numbers are for the installation disks.
Currently following versions exist:
1.2 no nforce support, download & compile from the tar.bz2 files.
1.4_rc4 nforce support "out of the box"
Installing & Upgrading nforce drivers on a running gentoo system:
# emerge sync
# emerge nforce-net
if you want the latest (unstable) 256 drivers:
# ACCEPT_KEYWORDS="~x86" emerge nforce-net