I couldnt find 16' sheets either , White oak is what I used. You can get everything at lowes or home depot. I was told that the wood species is less important than the fiberglassing and resin that you cover it with.
The scarfing takes time , but what ever you do DONT BUTT JOINT the peices togather. If you take your time scarfing , it looks nice. USE titebond 3 for the glue.
For more pirogues and designs visit
www.unclejohns.com he is located in Sulphur.