Once your kernel source is set up, you can easily compile modules against it. The easiest way is to get the debian source packages through apt.

apt-get install alsa-source nvidia-kernel-source i2c-source etc ...

These tarballs will appear in /usr/src/. When they are extracted they will be in /usr/src/modules.

Then:-
cd /usr/src/linux
make-kpkg modules_image

This will look for all source packages in the modules directory and build them against your kernel creating .deb packages for your convinience.