Okay, so some guesses here. I'm thinking you're in the Northeast, but a gardening zone would be useful. Also I'm guessing the house is largely south facing, given the position of the sun (based on the shadows), but perhaps you took the shots in the early morning rather than in the evening.
That said, a bit more info would be useful. If it's a sunny spot during the day, your choices will be pretty wide. I can imagine a nice Butterfly bush in between the windows, just beyond the edge of the bottom of the next floor, could work. There you will likely appreciate the fat and the pretty. Of course, there are other choices depending on conditions. For me, I think I'd keep the boxwoods off to the sides as you'll likely appreciate a star of the garden in the middle.
Early thoughts... fill us in on the zone and conditions.