Form to capture information and allow payment

Hi, I am trying to create a form that allows me to take down basic information, a dropdown menu for my product variations that affect pricing, a second step to the form that will take payment and submit the form. I would also like a graphic at the top of the form that changes as the product variation changes to show the price and possibly adding in a visual addition which makes it look like the item is on sale. Does anyone know how to do this?