I would like to plant an evergreen privacy screen to fill in a gap in my back yard. I have a yard that has some oak trees in the back that subject the area to partial shade. I have a couple of trees that I already have - an Incense cedar, a douglas fir, and a Nikko fir. Which of these do you think would be the best for such an application? I am willing to sacrifice growth rate for longevity. Any ideas for other plants would also be appreciated. Thanks.

Dennis