For 9 to 15 knots i would say the Ultrasonic because it is really wide.
I own a Ultrasonic, a Futura 111 and 133 and sailed the 122, 14x, 155 at Lahamy Bay Egypt. I like the US very much because its very easy to handle and starts planning early. Its great fun to sail with 9+ sails.
The Futura 155 is not more in production. The 141 Futura has 80cm width, too less for your required winds.