Hi Justin
I'm currently in the same process. I've used a fire board behind the tiles, you'll be able to purchase this from a local Builders Merchant, It looks very much like asbestos sheets but a little thicker. Ive attached this to the plywood lining using a gripfill adhesive and then tiled on top. The only problem I encounted was that the board isn't flexible and therefore i had to apply it in small sections to allow for the curvature of the boat. Not to sure about the type of tiles to use although my stove is a little Arrow Acorn so hopefully cracking will not be a problem!
Great name by the way!
Justin