Dynamic Online payment screens connected to Shopify - repost

Dynamic Online payment screens connected to Shopify: MUST be 2 separate screens that lead into shopify (like files attached) Open to any suggestions to get this to happen. - Can be html - Completed in shopify - Wordpress plugin template design Ideas welcomed to get end product like in files attached. Website for project not running yet, but I want code written ready to drop into website when required with instructions and a demo of it working before final milestone paid. The payments box is to be able to be used on multiple products, and individually changed. Need to be able to access and change the pricing/quantity options. (this is where a possible wordpress plugin design could be handy) Custom option to open a text box and calculate prices on a m2 rate. (calculate [login to view URL]) Needs to link to the next page, which is art upload. (artwork [login to view URL]) When that loads up, a text box with notes to upload to dynamically appear. Once art is uploaded, link the $$ to shopify to take payment. On the back end, the art, all payment details and shopify details to be sent to one email address in one form. Would like to specify the email address dependent on the options originally chosen - digital to one address, presized to another address.