I have a website that offers web design packages. I want to create a system that is pretty automated. So basically I sell web packages that include multiple benefits. There is an Addon page where they can buy additional pages, SEO & web maintenance packages.

Whats the best way for the customer input the details for the page: Page title, Page content, pictures if any, etc. I was thinking just emailing them after they purchase the pages and have them email me a text file back. Does anyone have some suggestions?