What is the most expensive surfboard ever sold?
-^that is incorrect actually. The most expensive surfboard is more like $100,000. There were 10 of them created by Marc Newson. They were nickel plated, however they were functional. He created them with the help of Dick Brewer, who's boards have fetched prices as high as in the $50K range.
Call a carpenter. A good carpenter will draw up plans for you that include the features you want/need and give you a fairly accurate estimate of the materials and labor, as well as a finish date. Talk to friends and family to get references for a good carpenter. When you speak to a carpenter, ask to see photos of his previous projects and for references from clients.
You would want to call someone who specializes in fireplaces and stoves for tips and ideas. For construction issues ask a carpentar for advice and price quotes.