indeed its been covered, as far as S13 driveshaft forget about it, its not going to work.
as far as S14 differences in lenghts are between the ABS and non-abs in the second part of the propller shaft means that if you do the swap, you can have any 5spd S14 1st part of the (some exception with are with 97/3 + cars) shaft, as the ABS lenght is the same for the auto and 5spd (but difference is still in thickness which can be a problem)... in which case try to source complete S14 5spd ABS shaft for best result and for the right year (95-97/3 are the same then its 97/4 to 98)
your good friend in locating parts:
http://car-part.com/