Custom Form with PayPal integration?

Hello,
Is it possible to have a custom form that processes payment using PayPal on WordPress? I have worked with other CMSs that let me create advanced forms and then I could tie in a PHP script to process payment when the submit button was pressed. This would process the form and store it into a database and also execute the PHP script to process the payment.

I have tried to look through the plugins but I haven’t found anything that seems to do the trick.

Any advice would be appreciated. Thanks.