About the ZBrush low poly object you can yet only make this

Use this Obj23dmWireframe converter
http://moi3d.com/resources

This enables bringing polygon data in an .obj file into MoI to use as a construction guide. Unzip it to some folder, and then you can run the Obj23dmWireframe.exe program. It will prompt you for the name of an .obj file to read, and after that the name of a .3dm file to create. It will read all the polygon data from the obj file and convert the edges of polygons into line segments, and then write those line segments to the 3dm file. You can then load that 3dm file into MoI and use those line segments to snap on to.