Hi! I’m sorry for the delay. All those screenshots are captured within ue4 (that’s why they are posted on forum anyway 
). Mudbox and 3ds should be enough (I guess you can achieve the same in any sculpting program). I don’t really know the difference between Zbrush and Mudbox… However, people I know generally prefer zbrush.
If I were to give use some advice - you should make a set of several alpha textures that imitate skin topology more or less. Then, when you’re sculpting using those maps, you can achieve very nice detail in a very short time. Examples:
They may look lame, but really get the job done