A lot will depend on working distance to subject and type of shot (headshot, half body, full body).
Generally speaking, the longer the FL, the more isolation one can get for the full body shot.
Anything from 50mm onwards can do headshots and give a shallow enough DOF for isolation purposes.
FF will generally have a more reasonable working distance (esp. for the longer focal lengths)
The 77mm is still rather usable indoors and out on apsc.
The 85mm gets on apsc gets a bit harder to use indoors.
The FA*85 is a smooth bokeh isolation by its sheer shallow DOF type of lens imo. (plus the nice bokeh)
The FA77ltd on the other hand tends to isolate by a very strong drawing style, color and contrast.
The FA*85 is big and often ends up as a very specific purpose lens (eg a portrait shoot session lens)/
77ltd is more portable all rounder and the lower encumbrance just means its taken out more for all purposes.
FA77 (apsc)
on FF
FA*85 (on FF)
50mm on FF can be very versatile too on FF.
from a A50/2
A50/1.4
Full body shots, I think do give the 135mm a consideration.
K135/2.5 on FF