Modify checkoutprocess for flowershop in zen cart

Modifing a zen-cart shop (1.3.8d) system for a flower shop. The Shop works online and i want modifiy the checkout process. The shop has a module for date delivery and, on each flower product detailsite, you can choose a greetingcard as well as a greetingtext. So now i will get the following structure/klicks: Articlesite: put a article into basket -> get a new site where article listet from a specified category and user can put items from this list in the basket (a simple categorylisting) -> second extrasite shows the date delivery and greetingtext to edit -> normal checkoutprocess go to loginscreen Thats all, i can show you online examples, my modified shop has on flowers details the oppurtunitie to choose a greetingcard and greetingtext this is realized with articleattributes, the date deliverymodul come from [login to view URL] I can give you ftp access for the shop. At this moment the shop is online but not active.