For the height, I was meaning an handlebar with a short rise = not from Brompton. To fin put the needed rise, just measure the height of the stem and the height of an M Brompton, the difference is the needed rise. This rise will be small, smaller than the rise of the original Brompton H handlebar.

But the reach is defined by the stem, not by the handlebar that should have its rise placed vertically (like the big rise of the Brompton M and H handlebar) to fold well.