Best third-party selling platform for quick checkout integration to optimize conversion rates?

I'm currently exploring the most efficient third-party selling platform to integrate with my Instagram for a swift and seamless checkout experience. My primary goal is to achieve quick conversion rates. I'm considering options like Shopify, Format.com, gumroad, and others, but I'm also curious about the effectiveness of using the official Instagram store. I'm seeking advice on which of these platforms offers the quickest checkout process and whether it's better to rely on Instagram's native selling features. Any insights or recommendations on best practices for this would be greatly appreciated.