So I started by downloading many of the Shopping Cart extension's at http://extensions.joomla.org/
After much playing I decided on "Tienda". Although in the early stages of development this is a very complete and professional extension.
The team at Dioscouri has really done their homework before starting this development, but the truly inspiring fact is how active they are in listening to the Joomla community and attending Joomla community events all over the world ... taking feedback onboard in the active development of "Tienda".
It is for this reason that I am sure we will see this extension in the "Editors' Picks" section very soon.
Thanks again to the team at Dioscouri.
I look forward to also looking into your other extension's now I know the quality of your work!!