When exporting a model from 3D ProAnimator make sure to export it with the .zxo format. This is the Zaxwerks specific format that will keep material, bevel, and object data. Then when you import the object into 3D Invigorator it will remember everything for you so you don't have to reapply the materials or bevels.
As of right now there isn't any 3rd party material pack that is prepared specifically for Zaxwerks products. However there are several sites that offer material maps packs that you can use to create materials inside of Zaxwerks products. Our friends at Rampant have a great texture pack that has 78 different metals: http://rampantdesigntools.com/product/rampant-texture-toolkit-v1/