I think you have this back to front.
A spherical image is one that shows 360 degrees around and 90 degrees up and 90 degrees down = 360 x 180 this a 2:1 aspect where the image is twice as wide as it is tall (exactly).
Where as a cylindrical panorama is 360 degrees around and less than 180 vertical. Typically around 90 to 140 degrees. Say 360 x 110
Does Panorama2Flash support cylindrical images? Yes according to the product page on the Easypano website.