Zone 6B: Privacy parameter tall grass/bushes/trees suggestions?

I have a 100'x 85' concrete slab in my backyard. I am going to be building a sauna, hot tub, and other outdoor features on this. I'd like to have tall planters with tall plants to provide privacy. The area gets dappled sunlight as the yard is shaded by a large 75yo oak.

What are some good options in MI Zone 6B and how big should the planters be?

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Thanks