TBM
UH-60Ms would have provided no appreciable capability increase over the current Black Hawk. Army chose the MRH because it had appreciable increases in range, payload and flexibility over the 'Mike'. The fact that it isn't working at the moment doesn't mean the original decision was necessarily a bad one - it's more to do with the program's painfully slow industrial ramp up in Europe and a corresponding lack of spares here, combined with an overly cautious (re airworthiness and IOC criteria) ADF.
By Knight Hawk I assume you mean the 'Romeo'...looks like an almost done deal.
Notification of possible MH-60R sale to Australia | Australian Aviation Magazine
The MRH/ARH build program will transition to through life support for both types - all DM work and upgrades through to life of type will be done by the workforce at Pinkenba, so it's more than just a few years.