I would not do stomach stapling surgery unless your dog comes from a line of dogs known to have frequent issues with bloat.
You can read about bloat here
In addition to the cautions listed there I'd suggest avoiding corn as many of these types of dogs do not do well with corn. You'll notice too that the list does not include doing surgery.
There are varying views on altering dogs particularly giant breed dogs.
Some feel the dogs should not be altered until the growth plates are pretty much closed which would be around 18 months or so. Some feel altering at 4 months when the cost of doing so is lower is a better choice. The bigger the dog the more anethesia costs are involved in the surgery.
A recent retrospective study of cause of death in another large breed seems to show that dogs neutered or spayed young appear to have a higher incidence of bone cancer than ones done after the age of three.
However an intact male dog can be difficult to live with and a powerful one like this can be a challenge unless really well trained.
As giant dogs tend to mature later than more usual sized large dog breeds do you might wait to alter him until he gets to puberty as that is a time when the growth plates begin to close.
Discuss the issues with your vet and with your dog's breeder if you know them. Knowing more about the health issues background of your pup could help you make decisions on the surgeries.
Hope this helps you!