Choosing a dog breed can be very tricky. Yes, there are things to consider such as the basic temperment of the dog, but there are also questions such as:
How much shedding can you handle?
Do you want a dog you have to have groomed?
Do you want a dog that is good with kids?
Can you afford a giant breed of dog? (Not only is just the purchase price expensive, owning a giant breed dog is like owning two large breed dogs in terms of everyday expenses.)
Do you want a dog that is good with other animals?
Have you had any dog experience, or dog training experience before?
How much exercise can you provide?
Do you want a dog that is friendly, or more reserved?
Do you want a playful dog?
Both Bullmastiffs and Dogue de Bordeauxs are great dogs, but require a handler who knows what they are doing. They shed and not only do they shed, but they also drool. So you will have a lovely hair and drool mixture. They are giant breed dogs that will be very expensive. Finding a good breeder is mandatory to avoid health and temperment problems. They aren't the most obedience savvy dogs in the world - definitally not a push button breed. Both breeds can be same sex aggressive towards other dogs. They are fairly easy going dogs and definitally won't need as much exercise as a GSD would, but they will still need exercise to stay in physical and mental shape.
I would check out this website
http://www.yourpurebredpuppy.com/dogbreeds/index.html to find more information about a particular breed of dog. Then if you are still interested, check out the national breed clubs and rescues. Get in contact with breeders and ask them about the breed. Meet various dogs from the breeders to make sure you are up to the sheer size of a giant breed, as well as the drooling and other issues. Have your mom get up close and personal with the dogs to see if the drooling or shedding will trigger her allergies. Then after all that you should make your decision on what breed you want.
