Firstly, I would make a request for the driver on www.ni.com/idnet so that we can at least track the interest in the driver and possibly look at developing one if there is enough interest.
When you use the 4339B driver with your device, what issues are you having. Does some functionality work perfectly whilst other doesn't? What kind of errors are you getting? Could this be explained by the differences in device spec? If you give me more information, I'll help you as best as I can, but without the actual hardware, this can be a difficult task.
Another option (but will cost money) is to contact one of our alliance members, who could develop the driver for you.
Let me know your thoughts.