As You asked:
9N is the original model,
9AN its successor
"B90" battery stick is easy to build, or go with Streamlight Stinger battery stick
(there should be some threads to be found convering themes like Streamlight Stinger battery for 9N, as well as B90 battery selfbuilt ones. At least I myself posted some concerning the building, pictures included)
high/low power of a bulb: makes no good results.
there is an output it is supposed to work with. Any reduction leads to extreme low output (if even more than a glow), nowhere to be useful. More power to the bulb:
therefore double bulbs builds were the way to go.
at the end - and to make me friends in here, in that sub-forum again ...
I can only give You something to think of:
I never liked the 10X, way too bulky. The 8X had only that one level. So double ouput and the size factor brought me to using the 9N for years.
BUT
that immediately changed when the white led became "as good" as lights in that output class (lets name it normal to medium powered flashlights).
the point was: my 1st mod to an 6P --> 18650 powered and an
XR-E!!! as led - the 9N was screwed.
Way smaller, same "feeling" with the high beam, multilevel (which works perfectly focused with the reflector)
((remember: the "low" bulb of the 9N has the same power than the typical maglight bulb. But it is nothing better than any mule to navigate around, or write reports, inspect something near, ...)
.. the 18650 form factor has me catched from that time.
And the XR-E is also quite a way form todays Diodes.
(therefore You will also find some posts from me, when someone asked for modding 8X or 9N to li-Ion, and/or led ... Sure, possible, with medium to much effort, but what for: for bringing along air inside a bigger light than "needed")