Well you really dont need the kernel sources to install the nvidia/kernel/glx drivers.
You could download the precompiled rpm packages.
But the kernel sources are on the suse 8.2 cd's. Just go to YaST2 and then choose install software do a search "kernel"
And if you look good the at kernel-source :: The source of the SuSE kernel.
Just click it on and install it.
Your Athlon Kernel is already installed, the kernel source hasnt anything to do with Athlon. because its just a source so the nvidia drivers will only use some source's to make the drivers for your athlon kernel.