Nathan,
Maybe you already have the idea, but what I do is make a new document in PS
Preset is film and video. Make your settings then save.
With you open photo/image in PS, go to image, image size. Resize to dimensions needed for PAL or NTSC, (notice the checkbox : constrain proportions)
ok
image again, then select pixel aspect ratio
select for PAL or NTSC
then, all you have to do is drag this photo into the new document you created at the beginning.
Thanks for your time.
Matthew Brown