Trouble trying to find Kernel source...

[Frank Charles Gallacher <franxg@bigpond.com>]

Greetings,

I am trying to install the driver for NVIDIA GeForce 6600 GT graphics
video adapter on my PC, running Debian GNU/Linux 40rl i386:

kernel version:
Linux version 2.6.18-6-686 (Debian 2.6.18.dfsg.1-18etch1) 

gcc version:
gcc (GCC) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)

When I run the nvidia-installer ("sh NVIDIA-Linux-x86-169.09-pkg1.run")
It tries to find kernel source from "ftp://download.nvidia.com"; and
fails, then bombs out when it cannot find it installed locally...

To build a kernel, I need "kernel-source" and "kernel-devel" packages
installed; (something called "linux-kernel-headers" is already
installed).

When I try to install them, I get:

Ni:/home/franx/Desktop# apt-get install kernel-source
Reading package lists... Done
Building dependency tree... Done
Package kernel-source is not available, but is referred to by another
package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package kernel-source has no installation candidate

my "/etc/apt/sources.list" looks like:

#
# deb cdrom:[Debian GNU/Linux 4.0 r1 _Etch_ - Official i386 NETINST
Binary-1 20070820-20:21]/ etch contrib main

deb cdrom:[Debian GNU/Linux 4.0 r1 _Etch_ - Official i386 NETINST
Binary-1 20070820-20:21]/ etch contrib main

deb http://ftp.au.debian.org/debian/ etch main
deb-src http://ftp.au.debian.org/debian/ etch main

deb http://security.debian.org/ etch/updates main contrib
deb-src http://security.debian.org/ etch/updates main contrib

Can somebody please help me with:

1. Is there a mirror somewhere that has these packages?
2. Have I missed something vitally important??

Thanking you.
-- 
Frank Charles Gallacher <franxg@bigpond.com>