While searching for stuff for my '99 Gen 2, I stumbled across some Gen 3 skids from a company called Rasta 4x4. Judging from their site, you'll probably have to call up to find a distributor, and the skids are aluminum, not steel. They seem to have skids to cover most of the undercarriage, though, and they do have a toll free number listed IN THE USA (probably forwarded to a call center in India

) Here's the link:
http://www.rasta4x4usa.com/grandvitara.aspx