Sam, every thing I do is with Hardwoods, except for the few portraits I do. Yes, these would hold up very well in just about any hardwood. In my scroll saw class, I teach my students how to compensate for suspect areas that could break such as widening the cut to make an area stronger. I routinely cut fragile items in 1/2", 3/8", 1/4" and 3/16". I cut all my Christmas ornaments in 3/16" hardwoods.Fortunately, I have a full wood shop. Table saw, band saw, jointer and planer, so I mill most of my boards. But I also buy thin boards at Woodcraft.
There are many online sources to get thin boards such as Heritage woods, Ocooch Hardwoods and even most of the scroll saw catalogs. Do a google search for Thin Wood Blanks. You will get lots of places to look.
One other source for you is Rockler. I know there is one in Ontario, not yo far from you.