A mixed plant screen is much more visually interesting (and attractive to wildlife) than a row of the same thing. I think the mix is up to you but check out the suitability of the two conifers for your area. Neither is very tolerant of high summer humidity.

Appreciate the feedback. definitely want a mixed border so happy to see I am on the right track. Looking for other suggestions to fill in the space. As for the two conifers, they seem to do fine around here. I have seen them in multiple places. I think we are far enough north the avoid the extreme humidity of the south - we are in Zone 7.

I would encourage you to run your conifer choices by the guys on the Conifers forum. Truly, I have heard many comments about the unsuitability of the spruce in particular in your area. Too little temperature variation and enough summer humidity to cause stress and both insect and needlecast problems. Zone 7 is not really a very good designation for humidity......it gets pretty darn humid in summer even in New England!

It's mild enough in my climate with damp winters and even though we tend to very dry summers, Picea pungens is just not a happy camper here. Hard to find a mature one in good health. They come from a very dry climate with wide seasonal swings - hot, dry summers and cold, snowy winters. I'd hate for you to invest $$ and time into a tree that will not thrive.