i also have steinberger spirit pro in black which is made in Korea.
The string spacing as measured is 49 mm at the bridge ,48 at the middle
and 47 at the neck.Taken that into consideration the only pickups
i have found with similar spacing are some artec P90 dog ears ,
but the dimensions of the dog ears do not fit in the cavities
of the spirit .Anyway the standard steinberger pickups are ok
for the moment except from the middle single coil which seems
to be not well balanced with the humbucker in neck and bridge.
I have been thinking of replacing the pickups a lot
and i would not prefer a blade pickup as i think they are for metal
which is not my cup of tea.
Would a standard pickup with 50mm spacing both in neck and bridge
work well in that guitar or there would be a problem with sound
especially in the neck position which has the narrower spacing?
People who have done the replacement with the standard gibson
spacing (Not the F-spaced which is the latest standard even for gibson),
have they noticed any problems ?
That would help me a lot make my decissions on what to use to replace
the steinberger pickups.