I bought these shoes from the Gentleman's Emporium, which sells everything from Victorian menswear, womenswear, Steampunk clothes and accessories, and Wild West everything (though I'm fairly sure that the clothes cross over from genre to genre).
I got these shoes from Gentleman's Emporium because I wanted to be sure they would be good quality and comfortable, but I did not know that they themselves get the shoes directly from Funtasma. You can get them cheaper from Funtasma through Amazon.
I tried making spats for them following this tutorial, but failed rather miserably. First I made them too small, then I messed up the buttons and buttonholes, then tried closing them with velcro, which did not end well. I'm rather traumatized now from my attempts at making spats. However, I found this tutorial from Festive Attyre, which I will most definitely follow the next time my costume calls for spats. Or whenever I feel like it.