Ok, folks I have considered seriously.
I have come up with 2 ideas, one is a Native American (Indian) Concept and the other is back from the days of D&D (Dungeons and Dragons for the uninitiated); Yes I am a real old schooler, been playing D&D since 74, back when the concept of RPG was not even considered but folks were playing them, when TSR was still in control and names like Gary Gygax and Jeff Grubb meant something
Ok, seriously.
Out here in the "West", the Native Americans still hold Rain dances as a sacred ceremony, but also in the Navajo (Pronounce Nava - Ho), they also have Shaman that will predict and "Control" Rain.
In most Western Native American cultures, there is what is known as Cochina (Indian gods of weather and seasons), and these Cochina can be represented by an appointed (For lack of better term), as the physical representation. These folks are considered to be weather wise, and callers of the Rain.
A Rain Mage if you will, also (regardless of age) considered an elder by level of respect.
Well if we put a Latin twist in it, and re-translate it back to English, you get one of my suggestions:
Rainmancer
For my next serious suggestion, I just reference the old D&D books, which have a foot in actual history.
In the D&D a person that is human, but almost all knowledgeable about a subject, is referenced in the same way in early pre-Saxon history. These folks were learned in many areas, but did not know everything. These folks were scholars, and scientists, and experimenters of all things, with one goal in mind. To expand one's knowledge and educate others who would seek their Council!
And this leads me to my next suggestion:
Sage
Here you go for now, my time is up at this system, I will be at another friends house shortly, as my laptop at home is auto loading Windows 7, and I am in the field.
I am always open to more suggestions here.
As a final note.
I am not opposed to a Japanese or Jedi system, but from a respected point of view, I believe that these terms can and should be used commonly by those that are comfortable with them, and not as an appointed position. The ranks in the Jedi order (Now considered and Official Religion of England), is strict and observed, but in the Japanese Honorific System, honors and entitlements can change depending on the situation and subject.
I consider Mr. Morley-Sama and GhostMatrix-Sama both Senpai and I accept the position of Kohai, or Padawan learner, and both are true, but in respect to say the subject of a Linux Distro, my title may change to Senpai when dealing with Mr. Morley, but will change back to Kohai when dealing with Caledfwlch-Sensai , but under the Jedi code, this is not true. The Jedi way, all though beloved by myself, and is a standard to live up to, may be too ridged in this environment.
This is why, with respect, that such titles utilized from the Japanese and Jedi code should be used by folks that are comfortable doing so, and not used as a way of identifying a skill set. Especially as many of my skills are not skills that DragnMage-sama or GhostMatrix-sama may have, but they do have skills, education, and experience(s) that I do not
For further materials on the Japanese honorific titles please consult the following:
http://en.wikipedia.org/wiki/Japanese_honorifics