I can't see any preset resize settings in the output module that would give you that, but you could create a new output module template with the correct resize and have the script apply that.
If the problem is that this still doesn't tag the output with the correct aspect ratio, maybe you could have the script put the output comp in another comp with the correct pixel aspect and render it through that.
I put the movie in a comp (1440,1080,1.33) cut one image and render it as a JPEG, but it doesn't work, it render a JPEG (1440,1080,1).
So it sounds like you do want the file to be tagged with the correct pixel aspect. I don't know about this myself, but I would say that if you can do it in AE manually, you can probably do it with a script. And if you can't do it manually, it's unlikely you can do it with a script. So if I was you I'd look into that first, maybe asking about it in a more general AE forum.