Welcome. I'm guessing you have narrowed it down to a canopy as you're looking at Fiamma and Thule. If you are considering the bag type that slots into the awning rail then Fiamma are the most commonly used/available. You will need a 225. The material on this has a width of 202cm and the bag is wider at about 236cm. You cannot get any longer in the awning rail. If you want one of the wind out cannister types then probably a Thule. who took over Omni.
Colin