You can do it yourself, too. I planted a root cutting from the cherry tree in my former neighbour's garden - the roots surfaced in my lawn and sprouted when scraped by the lawnmower - 15 years ago, when it was a skinny twig, at the east end of the garden. Now it's the height of a two-storey house, shades the garden in the morning and provides glorious blossom, privacy (as well as lots of cherries for both me and the wildlife) in a hot summer and good architectural form even in winter.
For faster growth, especially height and lovely blossom, try acacia: sometimes mis-sold as mimosa. Mine rivalled the cherry tree's height in half the time, even after being grown in a pot for several years.