Due to the time laps from the original post and 
my reply, I assume you already made a purchase, 
but, in all honesty, I think either would be 
fine. Neither cabinet would be air tight. The 
cel bag itself would be far more sealed than the 
cabinet. And any vapors that might come from the 
paint over time wouldnt be any greater than that 
of the cel acetate or the file cabinet paint 
degrading. As long as you keep your cels in a 
non humid, cool, and UV free environment Id 
imagine they'd be fine. Mine are in cel books, 
standing upright in a comic box in a closet, and 
they seem to be as good as when I bought them a 
decade ago. You could always ask dealers 
directly if you want a more expert opinion.