There is a black 20mm FA, the 31 Limited and a silver SMC Pentax-FA * IF AL 24mm F2
For portraits there are, besides may be the 100 and the older SMC Pentax-FA * IF 85mm F1.4, only manuel portrait lenses.
The Samyang 135/2 seems to be outstanding and not expensive. The Samyang 85/1.4 does not have very good reviews.
Oh I forgot there is the older Sigma AF 85/1.4