Based on what I’m using -
Lets see- for nailers, one or two, or maybe some use of a 1/2" drive impact wrench, light air sanding, filling the tires, spray painting with a touch-up gun or adapted down to an airbrush, general stuff, I’d recommend one of the 1 1/2 -2 hp, not awfully big oil-type compressors. The contractor-type portables, in other words.
A few things-
Air nailers don’t use much air, really, unless you’re nailing off lots of plywood fast with a good sized framing gun. Finish nailers, you’ll never outrun the compressor.
An impact wrench 1/2" drive ( and take it from me, the 3/8" drive impact wrenches are useless little things) will use a lot of air if you’re the Wood Brothers or some other pit crew, otherwise no.
Small air sanders, like the typical 6" random orbit or disc sanders will outrun a small-ish compressor pretty quick, but if you don’t mind a moment now and then waiting for it to catch up, no problem.
Spray painting: you’ll want to get an aftermarket or add-on water and oil filter for your air with any spray painting in any event, so oil or oilless isn’t an issue there. Get a good regulator, and they are cheap, and you will be able to get the pressure down to what an airbrush wants, no problem.
If, on the other hand, painting becomes a serious item for you, then a stand-alone HVLP setup will be on your list eventually. It is on mine, but not too soon. I hate painting.
This isn’t, after all, production work, where somebody is painting or grinding all day.
The main differences between oil and oilless are the oil types last longer and the gutsier ones are all oil lubed. And oilless compressors make such an annoying sound, after any length of time you’ll want to take a sledge to it.
I like the 2 HP and under size…and don’t be misled by claimed horsepower, you want something that draws around 15 amps at 120V. You don’t need to worry about popping breakers or blowing fuses with one of them, where around 5 HP you’re looking at 220V and a lot of juice, not something you can just plug into the wall socket.
I have a Hitachi…and I suggest you go with maybe a Porter Cable or Rol-Air. The Rol-Airs seem to be indestructible with decent care, the Porter Cables have the gauges and chucks mounted in a kind of instrument panel deal so they don’t get hit or busted off. My Hitachi, on the other hand, has non-standard ( 1/4" NPT is pretty much the standard size for air stuff on small gear like this) threaded gauges and such which are more to replace than replacing the whole regulator/gauges sub-assembly with more common-sized stuff. And the gauges are set where they can be banged and busted in normal, construction-type use.
Avoid DeWalt for two reasons. One; they are DeWalt and thus just Yellow and Decker, two; they owned Emglo, maybe still do, and the quality went all to hell. Stanley/Bostich compressors seem okay, their nail guns suck. Hitachi nail guns are the best, but their compressor isn’t, as I mentioned. I have had okay luck with a $100 Harbor Freight cheapo compressor until some moron ( the owner) decided to take apart the regulator/valve/ pressure switch assembly and couldn’t get it back together. They will sell you adequate regulators very cheap.
And, a word about hoses. The word is ‘rubber’.
Unless you live in constant 70°F+ temperatures, the PVC hoses will drive you nuts, they don’t like to bend when they are cold. The harder plastic ( ‘Coca Cola hoses’ they call them here) hoses the roofers love will kink, the flow is miserable for larger tools and they like to break - their sole virtues are they are light and they are very, very cheap. The reinforced plastic, sorta-flexy hoses that look a lot like the hose the rinse attachment on your sink has - kink city, you really want to keep them on some sort of reel, as otherwise you will have knots and tangles that will make you want to chop them into link-size pieces.
Go with the rubber, neoprene air hoses. They are okay in the cold, okay in the warm, the reddish ones are non-marking, they come in all sizes and lengths and thicknesses.
Air fittings- get brass, not steel. Brass doesn’t rust, it doesn’t wear out the other fitting, male or female, that you are connecting to, Harbor Freight has 'em cheap. I get them in half-dozens and stuff 'em in my air tool cabinet with some teflon tape. They do wear out after a while, just replace 'em. Hoses usually come without quick-connect fittings, and they are double-male threaded, so you will want a female threaded fittings for each end of your hose. Again, 1/4" NPT is standard, but there are 3/8" and 1/2" threaded hoses out there, and finding fitting for 'em cheap ain’t easy.
Anyhow- that’s my little air compressor rant. Hope that’s of use