I bought the Senco Super-Quiet single hot dog mini-compressor a while back for my business. The Porter Cable pancake compressor I had was larger, heavier and much, much nosier. I use the Senco with three different nailers: Porter Cable 16ga, Ridgid 18ga and Porter Cable 23ga pin nailer. Although it doesn't have the overall air volume of a larger compressor, it's truly quiet indoors and in confined spaces. It produces more than enough air to keep up with my nailing needs. The compressor is around $130 on Amazon and ships FREE. The nailers can be had at HD or Lowes or wherever. As for the nails in 16ga, I've had tremendous luck with Paslode straights. You can always find Porter Cable 18ga nails in any of the home centers.
FWIW, Porter Cable is offering a pancake compressor with two or three nailers at HD. The package price is very attractive BUT that compressor is terribly loud.
The small senco compressor is really quiet and very portable , but will not come close to supplying the needs of automotive tools. Impact wrenches, air ratchets, sanders and grinders use a LOT of air. check the requires cfm of these tools before you purchase a compressor
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