honestly? i think you are over thinking it. just plant a nice broad leafed plant and it will be fine. if you don't mind a bit of work, you can plant a small ficus 'benjamina' in the left front. then you can trim it to keep it small. basically, bonsai it, since this is a tree that grows 100' tall. it's a common bonsai plant and should be readily available to you. or, you could just buy a ficus bonsai tree and plant it in there.