Now that I'm a member of the Arboretum, I can order plants through their Member's Only Sale.
One of the items I'm eyeing is the Pagoda Dogwood (Cornus alternifolia ‘WStackman') they are selling in 1-gallon containers. It's an understory tree, will get 10-12' high and 7-12' wide, likes partial shade and a fairly moist soil. I have 2 areas it might be perfect for...
1) The east side of the house where we removed the Apple Tree (the tree in this photo). It only gets morning sun here and is near a downspout. I wanted a tree here that wouldn't really get taller than the house. Cons: I don't see this part of the yard too much and it's a pretty tree. Also, against the house, would it not be able to spread?
2) In the Southwest garden where I pulled out the Lilac bush (was not enough sun after the trees grew in more). It would definitely get partial shade here and be a companion tree with the serviceberry and I can see it from my window. Plus I wanted something tall for the back. Cons: It would have to be watered more here, and I'd want to built up the back a little more just to ensure good drainage. (In this photo is would go amidst the ferns, the old lilac branch is still there).