Nice model

just to clear a few things up about ZBrush, basically it is a modeling and detailing package, you can either make your model in ZBrush or bring a poly cage in from another app, at the moment it can handle around 2 million polys with ease, what basically happens is you drop your model to the canvas where it basically becomes like photoshop only you can use brushes to push and pull points you ca then use this as a normal map or displacement map to add to model in another program or render stright from ZBrush, which does have a very nice render if you spend the time learning how to use it effectivly