Aileen.

The photos you provided are relatively simple designs- clean lines of foundational boxwoods, bouyed by lines of hydrangea and azalea, puncuated by a few spruces and dogwoods. If you are devoted to this design I will draw you a planting plan of easily findable plant material.

There are two methods of managing a landscape- rigid and loose. Ridgidity requires active management- weeding, pruning, mulching, fertilizing and replacement. Loose allows native species to colonize and expand, and relies of healthy soils- you will mulch and spread compost but mostly allow the constituent species to rise and fall according to the season and location.

Either is fine, although native insect and bird species -and the earth in general- will prefer the latter. The tradeoff is that nature does not concern itself with aesthetics- it is raucous, changing, and chaotic.

I am a devotee of that native style of landscape, but understand if it does not conforn to your vision. 

Please google the designs of Gertrude Jekyll or Piet Odourff for examples of native gardens.

Let me know which you prefer and I will have further comment.