Hello,
where can I find and buy strong neodymium magnets with the shape more-or-less of a needle (eg very thin rods)?
Up edge of the needle North Pole
Down edge of the needle South Pole.
the problem with this idea is that, as it is, neo mags are brittle, and thier shape is limited.
http://www.kjmagnetics.com/ (http://www.kjmagnetics.com/) may have what you are loooking for, and I don't mean to be idiotic, but you may just try wrapping high gage wire around a needle and make an electromag, sometimes this results in transient magnetism - this may complicate things for you, however, I find that there are very small magnets for sale, and they may get the job done.
http://www.kjmagnetics.com/products.asp?cat=13 (http://www.kjmagnetics.com/products.asp?cat=13)
The longest neos I've seen are 3" as the field collapses due to flux density.
KT has the closest I've seen to that for which you are looking:
http://www.kt-magnet.com/permanent142030-magneticbar.htm
TS