It depends how you plan to work. If you pose the figures in Poser, you can bring them into Blender and sculpt any details you want to add. If you don't want to chang the pose after you started scuplting, this would work.

You could also use a programm like xnormal to create a normal or displacement map for your Poser figure and apply the fine details that way. You would need to render the image to see them, and you will probably have some losses.

With ZBrush, you can use a method called GoZ to bring your model into ZBrush, sculpt it there and send it as a morph back to Poser. This is very convinient, but I don't know if it's worth the price for you.

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.