Get a 5hp compressor as a minimum, it will keep up with just about any tool you use. I like 220 volt over 120 volt motors. Biggest advantage of 220 volt, you won't have everyone trying to borrow it. Not when they hear that they're going to have to run a 220 volt circuit for it. I have some family members who like to borrow tools, never return them, or break them, don't return them, don't take care of them, etc.
I have a rule, if I lend you tools, and I have to go get them cause you didn't return them when you said you would, you don't get to borrow tools again.
Good tools are a investment and are not cheap.
Get a oil filled compressor, they last much longer than the oilless compressors. Buy spare maintenance items when you buy the compressor, compressor oil (yes, it's a special oil), air filters, etc.
Never/ever use one of those regulator/lubricator systems on your compressor, you will comtaminate all your air hoses, which means you cannot use it for painting. Get a simple regulator, oil your air tools separately.
Buy a pair of oil/moisture separators (buy spare filters), mount one by the compressor, mount the other one 25 to 50 feet downstream of the first separator. As the air cools, moisture will drop out of the air. You want very dry air to shoot paint with, moisture laden air will give you fish eyes and other nasty stuff when you paint.
I use 2 oil/moisture separators and 1 chiller that I stick in a coffee can filled with ice cubes to cool the air before the 2nd separator.
One thing to remember, you are putting together a system. To make it all work right, you need all the components.
Good luck, a good air system is one of the best tools you can buy for your shop.