We don't own an H3 at this time, but either the red top or yellow top group 34 Optima should work out fine. You may also want to consider an Odyssey battery as well. Same concept as the Optima (AGM), but many will argue an even better battery...
http://www.odysseyfactory.com/product_list.htm
The PC1500 is most comparable to the Optima:
http://www.odysseyfactory.com/docume...0-001_0506.pdf