aspect ratios are difficult because you have to deal with non-square pixels and stuff. i render my stuff for DV(PAL) with a fire wire output. i use Adobe Premiere’s standard setting for this, which is 720 * 576, with a pixel shape of 1.096, whatever that means. rendering from blender i use 720 * 576 with a 1 * 1 aspect ratio. i’ve never noticed any distortion when i put my work onto miniDV or VHS.
maybe you should contact someone like Adobe or Pinnacle and ask them to explain pixel aspect ratios for you. they’re more likely to know than anyone here.
make sure you render at 30fps, even though NTSC uses the quite ridiculous setting of 29.97fps.