not real knowledgable about the lift leveling kit. i hear it raises the front up to inch and half. all you need to do is get an alignment after. i think it would look good on your truck. see if the link below works. if not go to ebay and punch in hummer h3, be on page 4.
http://cgi.ebay.com/ebaymotors/2006-hummer-h3-2-lift-le...temZ7992345391QQrdZ1