Hi,
I am a drop ship supplier, drop ship retailer, and a professional web developer. I would recommend Shopify. I use it for many of my own shops, I use it for my drop ship supplier site and recommend it to my drop ship retail partners. Wix and Shopify are really two different animals as far as how websites and ecommerce works. Wix appeals to some with its drag and drop interface, but ultimately it is very limited on function and ability to grow beyond a basic website. I did a quick search and it appears as though Wix does not have the ability to import products via CSV file (if this link is still correct: Link hidden: Login to view) If you plan to sell just a couple of products that you manually upload it may be a solution that works for you.
Shopify is an ecommerce platform first. It is built to be a store. Built in payment solutions include; credit and debit cards, Apple Pay, Paypal, and Amazon Pay. You can sell on different platforms from your Shopify site like directly on; Facebook, Pinterest, Amazon with limitations, Messenger, in person, and more. Search Shopify Apps to see the seemingly endless amount of apps that can be added for all types of special functionality. One of the reasons I chose Shopify for our Drop Ships supplier and retailer sites is because the product files easily export from the supplier and import into the retailer site. There is an app that syncs the inventory stock between the supplier and retailer so that retailers don't sell sold out products. You can read a blog post on our site about why we choose and recommend Shopify:
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I would say to first find out what is required to work with the drop ship suppliers that you want to use. Second what platform has the features you want and need. Don't forget to think ahead for a platform that will let you grow in size, design options, and functions.
If you want to compare platforms that are more on the same level I would recommend looking at BigCommerce and if you want more of a content first website that allows for built in ecommerce Woocommerce in a Wordpress site. Shopify is still my choice, but it all depends on what you need.