i found out years ago that the driveshaft shop was the best way to go! They have the knowledge and resources to get what is needed, and to my surprise better pricing that the parts stores. You will most likely need to resize the length of the driveshaft and have it balanced anyway.
Short story on my last project that needed a driveshaft. After sending hours at different salvage yards looking for a decent shaft i gave up and went to the driveshaft shop. They custom built me one from scratch cheaper than what the salvage yards were asking!!