You can use either Stripe or Gumroad for checkout and here's a quick overview of the difference between each.
Using Stripe offers lower transaction fees 2.9% instead of 8% offered by Gumroad. Stripe is ideal if you either already have a Stripe dashboard or don't have anything at all setup yet. In Paytable whilst your are setting up your product, in the 3rd tab (checkout) you can onboard to Stripe Connect from within our dashboard and we'll automatically create your stripe account and connect it to Paytable. It takes less than 1 minute to setup Stripe and add your bank details for getting paid.
Why Gumroad if the fees are so much higher? Many makers prefer to sell via Gumroad because it handles EU VAT automatically. Gumroad is an ideal solution if you are already selling info products in Gumroad. You can see Paytable as a membership add-on for gumroad where your paying customers will be sent post purchase to access your main database / gated content.