I went with the 60 series conversion. It is pretty straight forward and well documented conversion. The raw materials can be sourced from a solid axle mini truck, FJ60 or FJ62. You will need everything from the knuckles out and the steering arms. You will want to give strong consideration to replacing the bearings (wheel and trunions), new rotors, new calipers during the swap.
About the only thing easier is to get a disc brake front axle from a 40 and swap it right in.
You will really like the disc brakes. I ended up doing them in the rear as well.