Surplus Center should have a hydraulic motor that can do the job you want. They are in Lincoln, NE. They do not have a web site but you can get their catalog by calling 800-488-3407.
Just make sure you match the pressure and flow requirements of the motor with your hydraulic supply capability in order to achieve your 10 hp at 3400+ rpm...and that the rotation is correct if it is not reversible. That type of information is provided in the catalog.