Worked it out.
So apparently I had the drivers set the whole time really. Had loaded the 32 bit drivers and was building the ODBC connections from the SysWOW64 folder. All good. but due to a Windows glitch, I had been creating a User DSN with a matching user log in and User DSN on the server and they were failing each time.
In Windows, when you click on System DSN it give you a warning message that you are not logging in with local admin rights, despite being logged on with full Administrator rights. I found a blog that noted if you still go in and click "Add" anyway after clicking through the error message, you can create the System DSN and then the error message goes away for ever.
Seems to be working fine after creating the System DSNs, no thanks to Windows. Grrrrrrrr...