Yeah Young's got a point, dont overdo the definition (different from detail) on the lower parts, if your going into Z, the sculpt will change the base which may which may alter the original.

I know your after animation but I would get a sound mesh in there, no real details, but good base topology, then once in Z go from ther using the levles, keeping the base intact, getting your bang for your buck so to speak and no wasted work.

Hell though mate, your getting the workflow so go for what you want to!!