I think you do want a compressor that uses oil. Typically, the oil-less ones are noisier and in an unpleasant way. If you drain the water out of the tank after use, a good compressor ( w/ oil reservoir ) could last you the rest of your life. The only issue with one that uses oil, to my knowledge, is if you use the air to blow off dust, small amounts of oil (minute) can be spit out and contaminate the art. For interior use, I recommend you consider locating the compressor in a different room than you will use it for noise relief. Air hoses are cheap, but it is really worth it to have a hose or a short hose that you connect to the gun that is really flexible. They cost more but a stiff hose will drive you crazy, especially if you aren't used to air tools.
Also, the air tool recommendations about a tool that really lasts is not very meaningful, as none of the old designs are still in production. The good news is there are lots of good choices and they are less expensive than they used to be. Framing is a very easy life for an air tool. Most are designed for construction sites or industrial use. The most important characteristic is how far the tool drives the staple. I think an adjustable depth is nice, but many guns are designed to drive staples flush and others are designed to not cut through the fabric by leaving the crown proud. I have no expertise with which current guns are best w canvas, but obviously others here do.
Stuart