Lange: a limited model with more complications
Breguet: a chain and fuse watch
Technically: the Breguet is to be favored
Aesthetically: Lange as apparently thinner
A good compromise was mentioned in choosing a Lange chain and fuse watch, if the tourbillon is not the most important complication that you are after.
But: with the Langes you might have a problem to get one as any of the fuse watches are quite limited.
I would go also for the RL pour le merit in RG, as a chain and fuse watch is the summit in watchmaking IMHO.
Regards
Moritz