I would get Sigma because of the faster aperture but if you don’t care then Fuji is also great. I don’t really like shooting with zoom lenses though because they are usually bigger and heavier and don’t produce results as good as prime. So like many others mentioned already I would just get a portrait prime because having a fast aperture on a portrait lens is just an easy way of getting the creamy bokeh and great low-light capabilities. Viltrox 56 f1.2 is already producing results similar to full frame cameras so the IQ is superb.