No comment on 85 f1.8, never own one...
My vote is 50mm(=80mm to FF) for portrait. I used to have this lens prior 50L. On my copy, sharpness starts from f1.8 - f2.
I feel 85mm(=136mm to FF) might be to tight for indoor. I tried 135L on my 5D III few weeks ago, it was little tight for indoor.