If you're making a DVD then the only format is MPEG2.

As far as the frame aspect, if you create your video as widescreen, render it to widescreen, then you can set DVD Architect to widescreen under project properties and you'll get a widescreen DVD with no letterboxing.

BluRay can be MPEG2, AVC, or some other formats.

Your title thread question is probably not asked in the right context??
Try this _ what format should I render in an NLE to make a DVD with SCS DVDAPro authoring system?

Answer - use the built in render templates for separate audio and video streams for DVD architect prep. The video stream can be selected as widescreen if your source for the video on the NLE timeline is indeed widescreen in screen aspect ratio.

In Vegas try "tools", then "burn disc" then "dvd". Select frame rate and aspect ratio.

Thanks guys, I have to burn multiple copies of the DVD and when I render it to an MPEG-2 in the NTSC DV Widescreen through MainConcept the audio doesn't show up in DVD Arcitecht.

What are the audio settings?

Chap

"[I]What are the audio settings?[/I]"

In Vegas Pro, Render As:

Dolby Digital AC3 Pro

or

Wav PCM 48 kHz / 16 bit

If the audio and video files are not the same name (except for the extension), you'll have to select the audio file manually in DVD Architect.

The audio needs to have the same name and be in the same folder as the video I think. As well, there's DVD-Arc 'preferences' setting, as I recall, "Automatically link audio and video files' or something to that affect.
OTOH, an audio file can also easily be dragged to the DVD-Arc timeline.
Either AC3 or WAVE files will work, obviously a .wav file would be larger.
FWIW, Beware of the AC3 'factory' presets, the audio level is set for 'theater' PB loudness standards so I disable the encoder's dynamic range compression. I prefer DVD and BU audio destined for the home to be a little hotter and use the EBU or ATSC loudness standard and aim for an integrated loudness level of 21 to 25LUFS whilst still maintaining plenty of headroom to prevent downstream decoders and D/A converters from clipping. (which we have little control of) If an EBU/ATSC meter is not available (or understood), this usually corresponds to maximum peaks at around -10.0 or -6.0 dBFS (depending on heavy handed the mixer was with comp/limiting and such)

"an audio file can also easily be dragged to the DVD-Arc timeline."

It's an easy mistake to drag a file to the Menu timeline unintentionally, so I suggest adding it through the menu tree at the left.