Hi Hans,
As a starter, the following link will take you to the 16. Flak Division at Michael Holm's website:
http://www.ww2.dk/ground/flak/16fladiv.htm
Once there you can see the Flak Regiments subordinated to the Division in September, and follow the links to the Abteilungen serving under each Stab/Regiment. You should be able to dig up a little on all the Abteilungen if you go to the main page (
http://www.ww2.dk/ ), then click 'Ground units', then 'Flak units' and scroll down to schwere, gemischte and leichte Flak Abteilungen et al.
If this is not what you're looking for, at least you'll be able to build up a list of units under 16. Flak Division in September 1944 - I suspect there'll be quite a lot to track down!
Good luck!
Karl