James. I am using cartloom. It is a bit different from the traditional cart/payment type systems.
With cartloom you store your product info and checkout info on their server, and then your customers can checkout from wherever on the web you place the product embed.
So on you own website, you add a carloom page and the items are embedded from your digital warehouse (cartloom server).
Their stack makes a workable product list and product pages. If you need more design control you can use buy button embeds on your own pages.
The embed code works on other pages and sites. Like maybe facebook posts or email.