you can render it in zbrush with out having to reduce the polys.
or export a displacement map to your other render software as long as it supports displacement map
ZRemesher > make the quads more evenly spaced, this makes it where you can add fine detail any where on the object,
you can use Dynmesh which all most does the same but i like ZRemesher because you can have subdivision levels you can adjust high or low,
zbrush is not design for tri’s thats why the decimation master is a plugin to export to other apps,.
quads is what you want and with the ZModler brush it works well with quads not tri’s