@Vlad The Impaler if you are buying a compressor you might want to consider the lessons I learned.
1. Compressor makers lie about CFM, practically it is always less than stated. There are technicalities about how and where you measure CFM and it changes the number meaningfully. They almost ALWAYS go for the big number. It's like cars and engine HP v wheel HP... what they quote at the engine never hits the road because of drivetrain overhead. CFM quoted is often just a theoretical no load pump displacement number. What you actually get @ the business end of the line depends as much on the quality and design of the pump as anything.
2. Tool makers are optimistic about their tools consumption requirements, they always seem to need more air than stated.
Therefore if your air tools need 12CFM get a 15CFM plated compressor. That 6CFM gun of yours would probably need an 8CFM compressor to run it for big jobs. Air tools are cheap and good, if you need them... so consider what you might need to do then bite the bullet and OVER invest in the compressor. It's all down hill from there. Browse your tool wish list and get an idea of what you might need in the future. FWIW I have never regretted money spent on better tools!
For me 15CFM is about the number and well worth the extra cost.
These days, IMO, I would be looking at the oil free silent jobs with multiple compressor heads.
You will probably need a 220v circuit, I dunno what you get but we are all 240v so it's not something we ever consider.
I live in what is know as the 'High Desert'. It's fairly dry here, but it does rain on occasion. I've been using my compressor for a handful of years and never thought about draining it. It's a chinesium double tank affair that works well for powering a nail gun. I replaced the pressure sensor because it kept running and exhausting through the over pressure valve. Now it pressures up to about 90psi and shuts off til about 50psi.
I did install one of these on the output:
Campbell Hausfeld Air Cleaner, Air Dryer for Air Tools
just in case. The beads turn purple if water is absorbed. So far no purple, however when I recently drained the tank it had about 1/4 cup of H2O in it. There's a petcock on the tank for just this purpose.
another 'bare metal' thing to do is white vinegar. It etches the surface and allows paint to adhere. Works great on metal gutters too. Wipe it on and once it drys it's ready for paint. If you've ever seen gutters with the paint peeling off, that is the reason.