I too am looking for EDI integration with QBO. I am looking a 3rd party providers that offer integration with QBO for invoicing. Have been posting in a few places for feedback from  anyone with experience without much luck. I am looking at True Commerce SPS Commerce and B2B Gateway. The client needs to have EDI for Wal-Mart, Kroger and HyVee. Tge number of transactions are going to increase with onboarding of Wal-Mart making the automation part a real time saver. Let me know if you found a solution. I will do the same once I try