I would recommend a Shopify site. I've created a few already and found the platform to be very user friendly and focussed on e-commerce. Considering you're selling something lightweight, shipping would not be a major issue and rates are easy to calculate in Shopify.

The big thing to consider for your business is whether or not you want to build a customer base or sell products. Selling on marketplaces can be easier to set up but you are building someone else's customer base and in a sense building a house on rented property. Creating your own store gives you control and you build your own customer base that you can contact at any time.

Shopify is very flexible and is fairly easy to set up with lots of tools and support available.

If interested, I can go into greater detail about setting up and managing a store on Shopify. In the meantime, good luck with your business!