Hopefully, you might be able to try different hulls before you buy. I would not dismiss the Esquif prospecteur; it is a quality multi-purpose canoe that will fit your growing family. When people make claims about canoes tracking better than other canoes on flat water, they are often speaking more about paddling skills. All canoes will go straight with proper paddling technique. Some will go faster, but there are always trade-offs.
Edited to say I just looked at the "Canoe Canadesi" selections, they look like low quality poly canoes, similar to brands in Canada that one finds in major department stores.