I am jealous! How exciting to have a chunk of land with which to plan a garden and a new home.
I like all your ideas! Are you planning to grow any edible plants? Grape vines come to mind. The older I get as I garden, the more I like the idea of adding edible plants in with ornamental plants. Nothing like fresh picked veggies and fruit. Some fruit trees can make a nice privacy border, too. Though I do like your burch Betula nigra 'Little King' idea. And I love the idea of espaliers, too!
You are quite talented at design work! I am so excited for you!!! Keep us posted with what you come up with. I hope the ground is better than you think, so that planting will work out perfectly!