BTW, when shopping for a compressor, what you should probably make the most important spec your looking for is the CFM of air it makes at 90PSI. If you look at the air tools you'll buying, they'll have a requirement of CFM at 90PSI. Your 1/2 in impact wrench will probably be the one that uses the most air, or possibly the orbital sander. So find out what Impact gun you'll use, or orbital sander you'd sander you'd use, see what the requirement @90PSI is, and shop for a compressor based on that. You'll also want to regulate your air for your air tools at 90PSI as a general rule of thumb. You can always increase or descrease to your liking. Only time I turn mine down below 90PSI regulated, is if I'm running a hopper to shoot wall texture, sand blasting maybe, or of course running a paint gun in which case, I'm down to about 30-40 PSI. Then I also have an unregulated port for airing up tires so that I can run a full 125PSI to air my truck tires up to 65psi and it does it pretty quick where as if I use the regulated 90PSI, it takes a bit longer. And actually I only air up to 50lbs unless carrying heavy weigth, then I'll up it to the 65lb max.
14 CFM @ 90 PSI, 16.1 CFM @ 40 PSI