Not knowing all of your requirements, it seems to me you have a infinite number of choices. But I can offer a few suggestions:
– when you talk of order confirmations, I would recommend that you send the confirmation from inside of SAP from the sales order itself via output determination. You can configure different output types to handle the different formats. You may need a small piece of code in a requirement routine to control which outputs get sent…depends on your sales order design.
– I would recommend having sales order data in SAP different for each scenario, for easy separation/reporting. I would think you would want to be able to list all sales order types, for example ‘list all OOE sales order numbers from yesterday’. You could use a different ordertype for the sales orders. If you want the IDOCs to be separated, you can use different message functions/message codes.