feature set needs for shopping cart

[bluesgeek]

Hello, I hope you don't mind me asking for suggestions for ecommerce software (low-budget) that has the following features:

* admin access for offline order entry (back-end web form rather than pushing shopping cart front end)

* multi-user admin access with permissions (sales agents to access same offline web form for order entry)

* customize data fields in order entry (front and back end)

Thanks!