I have three Buhr oaks on my property, which I started from acorns. One is twenty-five high in just a few years, the other two, 10' high. They will easily compete with anything, anywhere, but will get to be a 100' high eventually. Just a thought. I would have a problem with mulberry because although the fruit is great, the mess and the wasps and creatures attracted to clean up the fruit dropping (numerous) must be taken into consideration. Stick with a hardwood, any oak, maple, etc. Cheers! PS. Stone's suggestion of a black walnut is of merit, but nothing will grow underneath it if that is a concern.