looking for a website template

hi

I am looking for a website  that will enable me to do the following.  

Allow a log on to the site for registered users. These will be existing customers in our business.

I wish to be able to set up products in a parent to child scenario. A parent product may have multiple children parts. Ideally
the parent will show on the site as an exploded view of all its parts in a diagram. All the children will appear underneath the diagram.

The user can order the child parts - this creates and order and emails to the company. There is no requirement for credit card
or payment on the website. This will all be taking care of in the backend system. 

Are they any standard website themes out there that would meet the requirements above ? 

many thanks

Mike