Let's start with the Blu-ray because that is the easy answer: 1080/23.976P with regions A,B,C enabled. That disc will play anywhere.
For the DVD, there is no true universal solution. An NTSC DVD with all regions enabled will play on 95% of PAL players/monitors, but very little equipment in the NTSC part of the world can display PAL. So that means you need to convert your PAL source before making an NTSC DVD.
If you are shooting the same program in both HD and PAL, why not make an NTSC DVD from the 1080/23.976P HD source?
Senior Editor/DVD Author
New York City