Hey guys! I am thinking about starting a collection of Lugers sometime within this next year and was hoping for some info on the many models of Lugers I should be looking for. I currently have one Luger which my great grandfather got when he was fighting in WWI. I would have had one that my other great grandfather got in WWII, but it was stolen

I am hoping that over the next 10 years I can acquire a very nice collection, covering all of the main model types of Lugers (Black Widow, S/42, etc.) but I have no idea what all of them are, and I can't seem to find a list of them on the internet.
thank you all for your help