Destroyed engine-case cx160b (Isuzu 4jj1x)

I have been calling all over the country and can't seem to locate a good used or rebuilt engine for my machine. It is a 2007 case cx160b with an Isuzu 4jj1x. A hired hand was running the hoe and he said it made a little noise and then it died on him. The crank shaft is broke in two and there is a hole in the front cover that I can stick my fist in. I had a local field mechanic take the engine out of the machine and assess the damage and he recommended finding a replacement engine. I agree that should be the most time and cost effective however I can't seem to find a good used or rebuilt engine anywhere. Does anyone have any advice on where to look for one or know where one may be located? Thanks in advance