I have a 2014 Dart 2.4L that hit 100K miles a few months ago. Mine's a stick so can't help you on the transmission.
I changed plugs shortly after I hit the 100K mark. My car seemed to run fine but when I pulled the plugs the electrodes were worn down to the point several had almost none left. Based on that, I would say that maybe 80K is a more appropriate interval to change them. I used NGK. So far so good. I don't recall what OEM were on the Dart, but NGK are factory on my 5.7 hemi Challenger which I'd changed a year or so back, so NGK was the brand in my mind as being the way to go.