For heavy items I use layers. First layer to protect the item from scratches, water damage, and from the packing material. I wrap it in plastic wrap and then couple of layers of bubble wrap. I am not familiar with your item so you may want to first wrap it first with a light cotton cloth then seal it with the plastics.
Second is to get a shock absorber foam around the item to provide shipping protection - firm but also gives to absrd without bottoming out. I mainly use pool noodles, either cut in half, whole, or in slices, depending on what I am packing. I did have foam from computer packing that had that right proporties as well. The great thing about the noodle is that it will wrap around odd shapes. It may not be the prettiest sometimes but it works and buyer feedback has been excellent.
Third, double box with a layer of absorbtion foam between the 2 boxes, or stiffer styrofoam sheets should be good do.
Here are a couple of pictures, the first is a heavy stereo component, the 2nd is a set of large speakers (12" woofers) with a noodle and other foam. I didn't double box these and they arrived in perfect shape. If they were $4,000 they would have been double boxed!!!!
