Another suggestion for containers...wooden barrels cut in half. Tyranenna Brewery in Lake Mills, WI sells their used barrels for $10. They're no good for brewing, but perfect for yard decor.
As for transplanting... the roots shouldn't be too much to deal with at this point, but I'd be worried about moving a 1st year. When I take my rhizomes up every 2-3 years to prune the root ball, they're usually about 2'x2' clusters give or take a little. That's with 2-3 years of growth though.