Magnolia 'Little Gem'-easily controlled to te height range that suits your requirements ben. Will generally form a clipped block of foliage over time though not as dense as the lilly pilly we chatted about. *Could be used as a "pleached" hedge(st
magnolia 'elizabeth': I know you said no more flowering trees, but I noticed the back has close to nothing in terms of flowering statement moments. Might be nice to consider a tree and some flowering shrubs, both of which are heavily included on this board.