You could re-convert them in WinAvi to get NTSC format .vobs.

Re-converting:
Start WinAvi (note: if unregistered then it will leave a sign in the middle of he picture saying "unregistered copy").Choose " AVI to DVD" then choose your vob (one from them) and set the target format "DVD", then "advanced" button and change format from "auto" to "NTSC" or whatever format you need (NTSC or PAL). Then "ok" and it will convert it for you!

Do this with each .vob file you want in NTSC.

If you have your re-converted files (vobs again only it's gonna be in the format you choose) then you can burn them to dvd.

DVD without menu:
If you do not want menus, then open a dvdburner software (Nero 7 have the option of burning dvds too, that's what I'm explaning) choose "dvd video". Here you'll have pre-made "audio_ts" and "video_ts" folders. Pull the .vobs into the "video_ts" folder then push burn. You have your DVD!


DVD with Menu:
If you want menus then you need a DVD descripter (like Ulead DVD Workshop or something similiar, I only know how to use this software but if you choose to use something else I bet someone will be able to help you with that software too).

In DVDWS, after the software starts push "new project" and type the name of the project in the field (this gonna be the disc's name), "media type" "dvd" then ok. After this you're in the "edit" tab. Here you import your files with the button "import from dvd", after import go to "menu".Choose background pic, then put a button on the menu by pushing the "Button" sub-tab then under this you can find a list saying "Buttons -General" . Choose the one you like and pull it to the menu screen. Click on the button you just created then choose "playlist" and set what it has to play (like play all). After you finished your menu you can burn the DVD at the final tab called "Finish"! You have your DVD with menu!