Funny, I think paint is the hard one. Impacts are easy. I've had no trouble running a IR 231 off a 4 gallon Emglo roofing compressor. Yes, it recycles after each wheel but for short bursts the tank, not the pump is keeping up with the tool. Heck, if the pump isn't turning then it's CFM is zero. My two issues with my compressor, similar to the one below, is it was rather loud in a small garage and my zip wheel killed the tank too quickly and the pump just couldn't keep up.
https://www.menards.com/main/tools-...ompressor/e810-4v/p-1463014285128-c-12910.htm
Anyway, another question would be how much do you want to spend and how big do you want. I've played with a number of smaller compressors. I can say my Emglo has worked well for many years (it's old enough to vote). It's a direct drive, oil lubed compressor. Not that quiet. Not much better than the infamous "oil-free" compressors.
I've got a CAT 5510A. It's oil-free but VERY quiet. However, it had a leaking fitting that was a pain to fix due to the glue+pot metal that much of the non-pump parts are made of.
I've messed with an older 20 gallon Sears oil-free compressor that was OK but I suspect the piston seal was starting to go bad. It's a totally rebuildable part.
I've got a 20 gallon Cambell Hausfeld belt drive, oil lubed pump compressor. Compressors like that are generally as good as it gets for 120V. They are quieter than the direct drive oil pumps but not as quiet as the CAT compressors (not CAT isn't the only brand using the same basic type of pump).
I've played with some of the dirt cheap ~100 8 gallon, oil free Husky/Briggs and Straton cheap compressors.
I've found there really isn't one thing that is going to be the problem. I generally wouldn't go too old as the tanks do rust out eventually. So long as they aren't repaired this rust should result in a pinhole leak which tells you to scrap the tank. In general I would accept NO rust on the tank (water drained from the tank will almost always show some rust).
Generally if the thing fires up and fills up you are probably fine. Do make sure it has an air filter. Some people seam to think those aren't needed.
Personally, if noise isn't a concern but price is, wait for something like this Husky or B&S to come on sale
https://www.homedepot.com/p/Husky-8G-150-PSI-Hotdog-Air-Compressor-0300816/302862402
That isn't a high end thing but for light use it will likely last many years.
Something like this with a bigger tank and oil lubed pump is better
https://www.menards.com/main/tools-...compressor/332614/p-1444423541745-c-12910.htm
Large tanks are slower to fill if you are starting from empty but they can really mask the lower air flow that's basically inherent in all 120V compressors.
Things like this are about as nice as it gets for 120V
https://www.menards.com/main/tools-...ompressor/332614/p-1444423541745-c-12910.htm?
They are typically as fast as any 120V pumps and the tanks are relatively large. They are also big and heavy.
This CAT compressor is an interesting option.
https://www.menards.com/main/tools-...pressor/cat-10020/p-1471978733665-c-12910.htm
10 gallon tank is reasonably and the pump is very quiet. However, I think the flow numbers are wrong in that add. The numbers on CAT's website are 4.4CFM @90 vs 5.3@90.
http://www.californiaairtools.com/q...mer-grade/2-0-hp-air-compressors/cat-10020sq/
Perhaps the models are different but look the same.