Call around to some shops that set up differentials. I bet for a carrier change it would be $150-250.
Also I should mention that with a shim kit setting the back lash is pretty easy, however you will need to make a differential case spreader. Pretty basic if you have a welder but on the 9.5 rear end I think it's a necessity.
I think on a 2003+ Gen 3 this would be a really good set up if you were not ready to drop 1000+ on an arb. From what I have read, the few people that have used an lsd with traction control have reported very good results.