Online retailer (catering consumables) seeks merchandise management system

I am looking for inventory management software for my online business (catering consumables).

The software should meet the following requirements:

• Customer and supplier database
• Flexible item management
• Ability to place orders with suppliers while on the go
• Inventory accounting (goods received and goods issued), inventory management
• Inquiries, quotes, delivery notes, invoices
• Monthly and annual sales reports
• Must be DATEV-compatible, as the outgoing invoice book must be sent to the tax advisor
• Revenue accounts may also need to be entered, but this is not essential.
• Use via a cloud, if necessary
• Support for mobile devices
• Transfer or migration of data from the old system would be nice

An online shop (TYPO3) is available.

One or two software workstations are planned. One is for the tablet and laptop hardware devices (possibly one workstation as a user license). MS Windows or iOS systems are used.