Chicago Pneumatic Air Saw P/N 7900 works very well. They are twice the quality of HF I would say. I have cut many mediums and never had a problem. The key is a quality blade for the material you are working with.
Yes, a small air tank is great for jobs too far from your supply. Use this approach with my air brad nailer many times.
The C-P is also made "off shore" but seems to be a better build.
