Don't know if it's available in your neck of the woods but the Buy, Sell & Trade magazine is full of ad's in the 'construction materials' section for cedar siding, including board and batten.
Not to my knoweldge. A search only brings up BuySell.com which is different but which might bring you some luck. Buy Sell and Trade is one of those free-to-advertise mags. which cost a couple of bucks to buy. You've probably got something similar wherever you are. Here, it's a great source of used construction materials, tools and ag. equipment.
I just finished an addition to my barn and changed the siding to Spruce Log T&G and stained it with Sikins Natural Oak. Came Out nice. I put OSB over the studs and then Tyvek vapor barrier. You could use Tyvek over the Cedar T&G and then your new finish boards.