B2B customer portal in zoho commerce

Does anyone know how I can achieve a b2b customer portal using zoho commerce.

I would like the following;

Integration with zoho books or inventory so items and inventory qty is synced and orders are sent across as sales orders or invoices in case a customer wants to pay offline

an ability to assign a customer a specific price list (wholesale prices, drop shipping prices or volume prices, so when they sign into the system, they will see the prices assigned to them

a bulk order function, which makes it easy for a customer to order multiple sizes and colours of one product, like t shirt, in one view. (see attached )

please help, if not with zoho commerce, is there any other way, syncing zoho books/inventory items to the portal