Prunus amanogowa - but it will get taller than that, that's for sure - anything defined as a tree will, other than Kilmarnock Willow, that has a fair spread after 3 or so years.

Amelanchier, it has bronze young leaves together with creamy white flowers. In autumn it turns lovely colours. Or try pruning a shrub to the shape of a tree ie remove the lower branches to reveal the trunk(s).

I've done that Volunteer with a lilac, it's kind of umbrella shaped and makes a great substitute tree.