Which plugin – when visitor presses buy a form should ask for more information

Hey
I am trying to built a site where a service is sold. Once the visitor clicks on buy I would like for a form to appear asking for more specific information – such as their email, name, and comment field for their order. I intend to use PayPal as the payment system.
So the visitor clicks buy now – the visitor is then asked to fill in ‘name’, ’email’, comment to order. Once this is done the visitor clicks on PayPal button to complete the order.

The order of the process could be reversed if needed meaning the payment is made first and then the information is entered.

Is there a plugin that can accomplish this?

Thanks
Crjensen4