Requirement is clear, i need you to build a shopping cart website exactly similar to existing site.
Wordpress is preferred.
Read the document attached. If you can not understand to read the document do not bid.
1.simply you need to create website exactly same of the given in the attachment
2.i gave additional information on how existing website works.
3. once you finish i should be able to have admin panel with full data exported and have the ability to export data for
new models in the future using import export using excel feature by mapping columns to shopping cart
4. paypal, authorize.net gateway implementation
5. layout of website is exactly similar, provide some example layouts for approval.
wordpress is preferred if not you can use joomla