There can’t be a more useful group of small deciduous trees than the Crabapples. They will happily grow in almost any soil (not water logged) in a very wide range of climates coping well with summer heat and drought as well as winter frosts and cold. Many can be grown as specimen trees or as screening plants and would be a perfect component of the mixed hedge.
There should be even more varieties regularly obtainable in the trade here in Australia as most nurseries tend to stock the common and therefore asked for varieties instead of encouraging gardeners to plant more unusual forms.
With that in mind can I suggest Malus ‘Pioneer Rose’ That was discovered by a friend of mine Helen Serpells in the Kewa Valley and is likely to be a cross between a crabapple and a commercial apple.
Its spring foliage is bronze and the flowers are deep cerise pink. The fruit is the size of a passion fruit and dark burgundy with pink flesh. If you can eat a tart apple you can eat this off the tree and it also makes fabulous pink stewed fruit.
I commercialised this form and find it a good doer that can be let grow into a far sized tree or pruned just like you would an apple tree.