I need an attractive shopping cart application for up to 500 items in multiple categories. The application will be used for normal eCommerce with ordering, payment and delivery. There must be stock control, so that any deliveries to us can be recorded and all dispatches after sales. The system must be able to produce invoices (with VAT), so customer registration will be needed. Notification of orders will be emailed, with invoices, after payment has been made. The system will also be used in the store, so invoices can be printed and email of notification is not required. There must be a facility to group products by 'source' so that all prices in a group can be changed when exchange rates change.
There is no rush for this and a full spec will be provided. Use of existing open source applications is OK.
After delivery we must be able to maintain and run this ourselves.