ODBC vs. MQ Adapter

I was wondering if anyone could provide some insight to an architect design for our project. We have 8 legacy systems that will feed purchase orders to the webMethod Enterprise Server and then to B2B Server. We are trying to integrate the systems as seamless and efficient as possible. As you can see, we have 4 legacy systems that has ODBC connectivity and the remaining 4 will feed PO to MQ since there is no other way for Enterprise Server to communicate with them. My current design is to have all the legacy systems send the POs to MQ and have Enterprise Server get the information from MQ. Then I thought why do that when you have some systems that can use the ODBC adapter. So now I am trying to find the pros and cons between MQ and ODBC adapter.

What is your opinion or thought regarding my current design? Should I use MQ adapters for some systems and ODBC for the other systems? Or should I just have all systems route the POs to the MQ?