I have sprayed poly in the shop with a gravity feed HVLP gun that runs off a compressor. I didn't notice any residue on shop equipment. However, I much prefer spraying lacquer because it dries quicker and you can apply two coats inside of a day.
As far as a gun, I would recommend a Porter Cable PSH1 gravity feed gun. Woodriver makes a comparable gun form less, but it doesn't include the regulator. I have both guns, among others, and those two work quite well.
Neither poly nor lacquer are food safe finishes.