If someone is using an Aztek airbrush, can you help me out.

I am buying myself an Airbrush for my birthday so I am doing my research. I plan on buying the Kopykake AirMaster compressor and the Aztek A470 airbrush set. My question is that Roland Winbeckler says the cake decorating style compressors require a threaded fitting on the quick adapter to work with the Aztek pen. Is this still true? Do I still need to get the adapter? He sells it on his site for $3.95. Can I buy this anywhere else? Also he talks about a moister trap? Do I need that? I also don't understand the difference between his Kopykake AirMaster that is $150 and the one that is $165. If the only difference is the adapter, why wouldn't I just buy the one for $150 and the adapter for $3.95.

Here is Roland's website.
http://www.winbeckler.com/airbrush_suppliespage_2.asp
http://www.winbeckler.com/airbrush_suppliespage_3.asp#Kopykake%20Airbrushes

I don't want to buy these and they not work together so any info would help.

My guess is the Aztec airbrush would require a fitting to be adaptable for the Kopykake airmaster.The chances of them having the same fitting is doubtful!! I would purchase the adapter.You probably could buy something like it at Home Depot or Lowes or somewhere which sells plumbing supplies but I would buy it from Winbeckler instead since they deal strickly in airbrush parts.I have the airmaster airbrush and compresser and I really like it!!