To answer your question the old Dadant style hives are the best choice for the bees hands down. ... Everyone else uses Langstroth and being able to be standard is a huge plus.
Well, Langstroth measures 50 cm x 40 cm, and Dadant measures 50 cm x 47 cm. This is roughly the size that I was considering when I talked about "wide" boxes. Both have roughly the same topbar length, so the big difference is that Dadant can carry an extra one or possible two frames. Since you prefer Dadant, I take it you would favour a "wider" box over a "taller" box, is that right?
Frame sizes are something a beekeeper chooses. Make them easy to work with. Also if you have the same kind as you beekeeping neighbours, it makes it easier to buy and sell hives.
Most beekeepers in my area use the Dutch simplex frame size. Simplex comes in two sizes, namely honey/super (14 cm) and brood (22 cm). Simplex doesn't have a jumbo size frame, but some beekeepers create a doubled honey box that takes a frame that is basically a "double honey-sized frame" (26-28 cm). Very few beekeepers hereabouts use any other frame size, unless they specialise in some or other weird hive.
Anyway, the frame size is not my problem. What I'm trying to decide on is how to structure the brood nest. Should I make it shallow and wide, or should I make it tall and narrow? In other words, should I make it 50 cm wide and 15 cm tall, or should I make it 40 cm wide and 30 cm tall, etc?