Krome,
Both the Omega models you attached look OK but the 2nd is the better of the two. I assume your generator is not a multi M$ investment or it would already have bearing monitors.
The advantage of the Omega over a modern HART unit, you can calibrate it without any fancy equipment. Take you RTD and stick it in an ice bath, thats 0 C, boiling water that's 100 C or close enough for a generator bearing. Of course if you have a decade box it's quicker.
Wire the RTD up with 3 wires as they show in the diagram.
The TX92-2 should suit your purpose, the manual says the Zero and Span can be adjusted by 25% otherwise range 3, just pick one thats a few % higher than your trip value
Good Luck
Roy