56cm Broam is what you want.
Because of the stack height on that size, you will be able to run less spacers below the stem, than on your current bike.
You will have to run a 10-15mm longer stem on the Broam to get the reach close to matching your bike.
Main thing I want to point out re the Broam is the 450mm chainstay length. Much longer (pedestrian feel) than your road bike.