No affiliation, This is just the board where you will find toy stuff...
Guy has set of Birfields and inner axles in GA. Price is not too bad IMHO. Should fit your application. He might separate the birfs from the inners if thats all you need.
You need to get a new snap ring for the end of the birf. That might be a dealer only thing however. The snap rings are usually destroyed getting the birf off of the inner. Or if you get the whole thing just drop it in.
Good Luck. You also need a 54mm socket if I recall to get the hub off.. they are like 17 bucks online. or at your autodrone store. you dont reef on the nut so A "high quality" socket is not really an issue.
Also I would read up on the tech site of Ih8mud on how to remove and install its not bad, just real greasy.