We have bought lots of spices from Spice Treckers https://spicetrekkers.com/en-ca/ in Montreal. They're also known as Epices de Cru en Francais. Really excellent quality and selection, and they also ship via Canada Post.

Also highly recommended.

I just searched for 'cowboy shirt cotton' and got lots of images that seem to match what you're looking for. Lots of variety in the amount of stitching and other design elements too. Hope this helps!