If the 1 litre Kodak Rapid Fixer is available, it has one particular advantage.
It comes in two parts - the fixer concentrate (part A), and the hardener concentrate (part B). Part B is quite strong sulfuric acid (among other things).
I mix up and use the fixer without the hardener.
And then when I am toning, I finish off with a treatment in the hardener (mixed 1+13) prior to the wash.
Toning can soften the emulsion on prints. Post-toning hardening is recommended by Kodak and others.
The up-side: two chemicals in one purchase.
The down-side: the Part B hardener makes the 1 litre packages of Kodak Rapid Fixer a "hazardous item" for shipping purposes.