I would check with Rosewood Diesel. They are good guys to deal with and reasonable prices on 7.3 injectors. I am not sure if they do 6.0 or not though.
Warren diesel does a really good job on injectors and turn around is right around a week. They did my nozzles for my 5.9 and I know of a few guys who go to them for 6.0l injectors. They are out of Pa. Look em up
I would suggest Warren as well I am biased towards Jesse's injectors that is why I personally run them and would sell them to anyone and be sure that they would be happy