I've been told before that a NTC 3kohm thermistor is the right one for Mach2 replacement.
However, if you have any concerns, and just want to make sure you get the right one for sure, just PM the owner of EPUK (Phil) and he shoudl be able to arrange one for you.
I don't know what EP charges for a probe, but at least it will 100% be the right one for you.