The 90 fs will fly the Airtourer in a very scale manner. For many years I owned a Airtourer putting hundreds of hours in the aircraft.
The airtourer was available in 100, 115, 150 hp fixed pitch and 150 constant speed versions. Some were later modified to 180 hp, so scale aerobatics with the model are close to the 150 hp version.
The 90 fs will not give you unlimited vertical but plenty of climb performance.