We have more than our fair share of 6.0 Diesels in our fleet, to tell you the truth they have their problems but haven’t been near as bad as the newer 6.4 diesel.
Cracked injector tips are very common but I’ve never had one that broke off. We have also seen broken rocker arms on many of them.
If it really needs head work or something more I would seriously consider a complete reman engine from Ford. It will come with all the updates and a warranty good at any Ford dealer.
I don’t know what a 6.0 installed goes for right now but I just had a 6.4 Ford reman done on a F550 installed and out the door for just under 14K.