Building a hearth and platform for new wood stove Cob?

I am installing a new wood stove, it will be the primary heat source for my house.  I will be installing a Hearthstone Manchester, and I need to build a platform for it and possibly covering the wall behind the stove as well. I had been thinking of making a concrete base but am wondering if cob would be a better option. I found a blog where someone used cob and inlaid glass and tiles. Will this get too hot. I’d hate to create something beautiful to only find out it will explode or shatter. Also, for collecting thermal mass, is cob a better option than concrete? Here is the link to the blog i found, I haven’t been able to find any other source online for constructing a base out of cob. http://oko-organic-clothing.blogspot.com/2010/10/playing-with-cob-mosiac-adventure.html

I suggest you install a tube under ground or through the floor to use as a fresh air inlet for the fire. If set up properly it will reduce drafts through the house as the fire draws in air to burn.