Youll need at least 8 CFM and a 3/8 hose and adapters out of the compressor. My cheapie 130$ Harbor freight 22 gallon cant keep up when I hooked my 1/2" Snap on Impact to it. Felt extremely weak, and didnt sound right. MY father and brother (Contractors) can run their nail guns off of the small pancake compressors no problem.
+1. I had a cheap 25 Gallon single stage noisy as heck compressor. It always struggled with the 1/2 Air impact guns. Be prepared to wear hearing protection if you use a small compressor and you are doing something major. You also find that if you are working on larger bolts etc, you will get a limited run on breaking loose larger fasteners while you need to stop and let the air tank refill to get the maximum torque available. That is a major pain after a while.
I Finally found a used 60 Gallon 240V compressor on Kijiji that I upgraded to. What a difference in performance and less noise to boot! I got a heck of a deal on that compressor. Guy sold it for $250. Cost me about $120 to run a 240V line to my garage with new breaker and conduit etc. I sold my old 25 gallon for $100 (I got it for $80 about 8 years ago).
Pancakes like already mentioned are good for nailers etc. These days you can get a battery powered Brad nailer. A lot of people buy the HF cheap upright compressor for under $200 bucks. They sometimes tie in an Air Pig secondary tank for better performance. Check Youtube for possible solutions.
Snagglefoot, I see that you are in Canada as well. Have you looked on Kijiji or can you get to a HF in Washington State or that's not a viable option for you? Keep searching Kijiji, you will find something if you are persistent.