Custom fields required

I need 4 custom fields adding to the store 'add product' page. I then need these four fields to output in a seperate location, only when the purchase is complete. The location can be a downloadable file or a _blank page or iframe I have an css/html page that I would like the outputs to be posted to in 4 seperate divs, it must ineteract with the current store features ie. privacy settings, membership levels etc. Please provide details that will confirm your knowledge of the boonex structure, I need to communicate quite detailed guidelines for this to be a success. Thanks Martin