design a flash planner webpage to stitch into existing site

So what we need is an ecommerce site (done by us) then an option via a banner saying ‘online designer click here’ which takes them to a flash designer page like this [login to view URL] the only difference is that our flash project will be ecommerce i.e. everytime they add a cupboard unit to the wizzard it adds on a set price and adds this all up and offers a checkout option using paypal. The other diference is that we may need the user to draw the shape of their room as this example only gives fixed shapes and what room is going to fit into a fixed shape? Or maybe both options... We will do all graphics and visuals so just the flashwork needed. This will all be hard coded obviously so will not be updatable by client. We will need all original source files upon completion.