You could use, http://www.gastite.com/products.php?...2&idlink=link3
which is (CSST) Corrugated Stainless Steel Tubing. It uses compression fittings, so you wouldn't need to flare copper or thread black pipe. It would be cheaper to install black pipe, but faster and easier to install CSST. HVAC wholesalers sell by the foot, but may only sell to a licensed person.
In Ontario, Canada when your're using a hose to connect the BBQ, the shut off valve must be installed outside as close as possible to the hose. Also if you are the owner of a detached home, you can legally do all the work yourself. If it were a newly installed appliance a licensed person would have to activate it. Check with your local codes and regulations.