They basically just want an NTSC DVD from you. DVD is only pal or NTSC so there’s no question there.
You need to set your bitrates at an optimal level so you don’t spike over the cieling set by the spec….this is around 9mb/s
How long is your piece? With that info you get get a bitrate calculator to determine what’s best. Use Ac3 audio as well since it doesn’t take up so much bandwidth as PCM.
Personally I think you should hire someone who knows DVD and encoding since this will go out to be sold. That’s just my opinion….I wouldn’t do lighting or camera work myself since that’s not my experience….same in your situation.