Oscar: thank-you! Gocommerce is exactly the sort of thing I was hoping to find. Those Netlify devs are doing some amazing work. I hear you loud and clear about self-hosting. I used Woocommerce on a small eCommerce store many years ago and thought it was great at wrangling the monster that is Wordpress into a slightly different beast. I had not realised that WC could be used programmatically. Although it's not quite right for this project, I'm keen to experiment with that option in the future. Thanks again for your ideas.