Here's a little info in DVD+R:
In case you are not aware, DVD-R and +R are not hugely different. Just make sure that your DVD Burner can record to both formats. If not then you may need to use the DVD-R only.
Brands... If you are getting this mass produced then you shouldn't need to be concerned with the brand? That is something which the Mastering/Duplication House will deal with.
It's important to make sure the project length is compressed to DVD format so it and any menus and other media fit on a DVD-/+R disc (i.e. fits on a 4.71GB disc).
Hope that helps,