3 Litre Patrol, Where to go for Motor?

My father rang me today with the news that he's '01 3L patrol appears to of hemoraged internally.
With about 210000k's on the clock, He went to start it after it has been sitting for approx 2 weeks, only to find it hydraulic itself.
Oil appears OK but its missing some coolant, He also noticed that it hasn't been quite right for some time.
He may get away with just a head gasket, or it may be something more sinister, such as cracked head, won't know till they pull it apart.
What I'm after, is what have other done (worst case scenario here) and how much has it cost them when faced with possible major rebuilt on the 3L?.
Dad is working in Kalgoorlie and doesn't really need it (patrol) but was gunna get rid of it cos he no longer trust's it to tow the 2.5 ton van, and is considering trading it in straight of the back of the tow truck!
Shane