I've just gone though the same issue you are dealing with. Trust me by far the best bet is to stick with your original trans, pull it and rebuild it yourself or have someone do it for you. All the gas transmissions from junk yards have the cable clutch and are out of a 30+ year old truck that could be just as bad as the one you have. Just converting the clutch will cost you more $ and time wise than a rebuild I guarantee you.

The internals of all 4wd are identical and the internals of all 2wd are identical for the 4 and 5 speed respectively. So you can use a junkyard trans for parts if you need any. Usually a rebuild kit with synchros is all you will need, and tool wise a Posi-Lock TJ1 puller as well as the harbor freight gear splitter puller is all the special tools you will need.