Best Portrait-Lens for ist-D?

[Rolf Brenner]

Hi all,
what do you think is the best portraitlens (with AF) for the ist-D?
Should i keep my Pentax-F 50mm 1:1.7 or should i go for the Pentax-FA 
50mm 1:1.4?
I don't wanna use my 85mm lenses (FA and A) on the ist-D for Portraits 
because you are too far away from the person (on 35mm i never use 135mm 
lenses for portraits and my 85s will behave like a 135mm on the ist-D)
Thanks in advance
Best Regards
Rolf