I own neither because I am very partial to detachable magazines, but they are both safe choices and good value. Mossberg had to recall some early production ATR100s because of defects in the bolt but I think you can safely assume that is sorted out, especially if you get one with a fluted barrel as that is a recent addition. The Stevens 200 has a more established reputation which may be a factor if you consider potential resale value important, but I think the best criteria would be if you can get to handle an example of each, choose the one that feels better fitted to you. That can be a significant difference in how well you shoot a particular rifle, regardless of what it might do from a vice on a bench.
And like some have already said, the Marlin XS/XL7 should be on the list for this sort of rifle, too, but as you say, you've already eliminated it. For those who don't like the look of a particulare plastic stock, Krylon Fusion camouflage spray paints can fix it. Most triggers are adjustable, if not by the user, then by a gunsmith. (And there is a detachable magazine conversion for the Stevens200, but it is from a U.S. gunsmith and I am not at all confident it could be exported.)