birch wine

[Vin des Prarie]

Me and my old man just brewed three batches of birch wine (Betula Papyrifera). One just straight un-processed first run birch sap. The second was reduced sap by 60%. The third was un-processed as well but we added 5 lbs of naval oranges to the fermentation process. All of which turned out very different but one of a kind exellence in their own ways ranging from a light amber to crystal clear in color. I'm now looking to expand our horizons of flavor manipulation through casking in birch barrels. However I know nothing about this step nor do I know where to find or know how to make the barrels. I'm pretty good at following instructions to build my own, but I'd be much more happy to order some birch barrels. Anyone know where to start looking? The second question is do these barrels need to be charred, or roasted? I would assume it would depend on the color and flavor that you desire...... I dunno, any insight?