NEC 3500 is a good choice. I think you have read most of the reviews and threads to make this decision.
I will say almost all (maybe 99%) of the DVD Players support DVD-R media, but only a few of newly designed DVD Players support DVD+R.
But with bitsetting process to set DVD+R's BookType to DVD-ROM, it's about 99% DVD-Players will be able to read them.
My personal suggestion for the media is........not to buy too many same brand same model/type's media, but try to buy more different medias and to test them, although this takes time