while I'm here I will say this: I think that looking at the Winchesters and saying 'if they were around in real life they'd be vigilantes' when discussing their class is a bit over literal. the question is where on a more thematic level son places them, and how they interact with class. so I think for me maybe what's more important is how their careers place them as outsiders to, but also protectors of, suburban middle class america.
beyond that it's important to recognise that spn's position on class and the way those themes are dealt with varies widely across the show, and even within seasons. like in the later seasons it's more or less thrown out the window from what I can see, while in s1-5 it's a pretty key aspect of the show. so I think asking what class the Winchesters are part of throughout spn is probably the wrong approach, and it would be better so assess how spn approaches class at different stages than to have a definitive take