Go look through the Configuration.h file. In the RCBugFix branch (which is the one you should be using) the stuff to setup the probe is all together. The only magic for the Inductive probes is you won't need a servo to be defined. And typically, the Inductive probes have a postive (not negative) Z_PROBE_OFFSET_FROM_EXTRUDER.


There should be good comments to guide you on how you want the probe setup in the Configuration.h file.