You do not need linux binary compatibility to use the nvidia driver. It runs natively but there is only a 32 bit binary though. I find the FreeBSD binary to be more stable on my system than the current linux binary on linux but maybe thats just me.
The three ports you will probably want are:
-x11/nvidia-driver (driver itself)
-x11/nvidia-xconfig (automatically configures and updates xorg.conf)
-x11/nvidia-settings (gui to manage all your settings)
Enjoy