This is a minimal PayPal setup. Note that you can use PayPal even if you do not have a PayPal account. And in either case, you can keep the information you provide to us separate from your credit card information.
Your order of Comeau C/C++ may involve unique pricing, etc., so please contact us beforehand and verify things.
Your order of Comeau C/C++ still requires you to fill out a Comeau order worksheet. Remember, information you provide to PayPal such as credit card numbers, etc is not passed along to us -- see How does PayPal keep my information safe?. So instead of providing payment information in the payment box of the worksheet just check the box on the worksheet that you'll be using Paypal.
Do not make your PayPal payment until we have accepted your order worksheet.
Email us if you have any questions.