Then converting all of this footage to DV first is not really an option. I suugest you take a look at native MPEG editors (VOB files are essentially MPEG files). The one I have most experience of is Womble MPEG Video Wizard -
http://www.womble.com
Simply copy all the VOB files to you hard drive and you'll be able to edit them with Womble. You'll need a seperate application to author the DVD after exporting the video from Womble in DVD compliant MPEG. As you don't need anytging fancy, something like Ulead DVD Movie Factory would be enough.