I don't know if this is already known, but quite by accident, i discovered it's possible to make hair styles longer, and also to apply hair upside down on haptek head characters. Using this trick, i came up with the extended size head shown below. Not sure how useful this is, but maybe the experts here can make use of this idea. I thought i neat that the standard size head can be made taller. The hair moves just like it was part of the body.
Here is the .hap script i used -
#Haptek Version= 2.00 Name= upsidedown.hap HapType= script FileType= text
##standard
load [file= data/standard/skins/hair6_2EXP.htr]
Scale[figure= hair6_2EXP x= 1.0 y= -1.5 z= 1.2 t= 1]
\translate [figure= hair6_2EXP y= -9 z= 0]

Regards
Davy