I picked up a head from a late model ford laser with the B6 for not much.
the Fourth generation (KJ/KL/KM; 1994–1998) laser also ran with a B6 and apparently has 'roller rockers' of sorts.
the Fifth generation (KN/KQ; 1998–2007) has the ZM-de engine you speak of as well.
https://en.wikipedia.org/wiki/Ford_LaserI haven't done anything with the head yet. Its still as grotty as the day I picked it up. Ill clean it up this week and take some photos of that one as well - It might be an easier option / supply of the B6 head.
Not that it matters much to me - im still going with my early KC laser head as ive already done all the work to it- but it may yield some good info / options for others