Wholesale distribution software/online store

I own/operate a small wholesale business. I have several suppliers and I supply numerous retail customers. Currently, my order processing, invoicing, and payment reconciliation is done manually for the most part. I am using excel spreadsheets and google docs, along with Quickbooks. It is a lot of work and takes a long time. I want to automate as much of it as I can.

My needs:
*Customers can login online to place secure orders easily
*The system will generate purchase orders to be sent to each of the different suppliers
*The system can batch purchase orders and send to each supplier on a weekly basis.
*The system will interface with Quickbooks and use the purchase orders to automate as much of the invoicing as possible.
*The system should be able to handle multiple suppliers/manufacturers and numerous customers.
*The system can generate reports for each purchase order to detail the total wholesale cost of the order, the invoice total, total wholesale cost per supplier, and my total profit.
*It would be a bonus if the system can export purchase orders as an excel spreadsheet when necessary.

I don’t know if or how this is all possible, so any help/advice is greatly appreciated!