It is recommended to use the optimal resolution of your display. This will result in the display not having to resize the image and give an 1:1 ratio between the graphic pixels and screen pixels.
It is also recommended to run as low vertical refresh rate as possible. Most LCD, Plasmas or Projectors screens will look as good in 60Hz as they will look in 100Hz. The only difference will be that the DISE software only has to render 60 frames each second instead of 100 frames / second.
There are no problems having different output resolutions that match different displays and still run the same content on all of them. The result will be that DISE will resize the content during playback using the graphic card high quality hardware resize. This will be a much better result than having the display resizing the content on the display end.
Read more: Windows XP: Change your monitor resolution - Microsoft
Read more: Change screen resolution - Microsoft
Read more: Change screen resolution - Microsoft