If you will do a search of the posts on this site and this particular camera, you should find lots of discussions on Matteboxes , accessory lenses , filters as well as tripods etc.
When buying a Mattebox you need to be sure and take into account whether you will be using lens attachments such as wide angle converters and telephoto converters. These accessories are typically larger in diameter than the camera's basic zoom lens and may require a larger mattebox to insure proper fit and no vignetting (part of the image blocked by the shade).
We offer a number of accessories but there are certainly other options as well.
Can't go wrong with Century Optics, stzasan. They're the best for DV lens attachments. However, their prices can be a little high for some. I'm currently using a Formatt matte box, it's cheap and does its purpose decently, but I'm sure the other pro matte boxes with rods and such would be much better. At least with the Formatt matte box you can get seperate rings to use your WA and telephoto lenses with it, but at the cost of slight vignetting. But, if you can afford it, I would highly recommend Bill Turner's recommendation of such well made products.
Here's a picture of our Z1U with full Cavision 4x4 hardshade set-up.
People have written about Cavision versus Chrosziel ad nauseum, so I'll just leave it at the fact that you have to invert the mattebox (filter stages load from bottom instead of top) due to the Z1U's incredibly in-bred and obsenely protrusive built-in microphone.