Hummer Solutions has a shovel/axe rack that fits on the Gobi rack. It has a simple design, easy on-and-off loading and cheap.
The kit also includes a cable lock that prevents the tools from being removed (or used to break into your H2!!!).
It is a new product and not website-a-tized yet, but you can get more information and pix from their customer support group via email:
support@hummersolutions.com
Good luck.