There is currently no conclusive evidence that elevated feeding makes any difference.

More effective (but involved and expensive) is a preventative stomach tack (gastropexy). This should not be attempted by a vet who is not extremely experienced with them, as they can go very very wrong if done incorrectly. If he is going to be anesthetised for another procedure such as neutering or a dental, the pexy can be performed then.

General daily prevention can be assisted by feeding small meals, not allowing him to exercise after meals, and requiring him to eat slowly. There is a dog bowl currently on the market designed for food-bolters which has plastic protrusions that the dog has to eat around, slowing them down. I have not used this bowl, but it looks like it could work.

Familiarize yourself with the symptoms of bloat, and know which vets will accept calls after hours. If possible, screen them for familiarity with GDV correction so that you can give him the best chance at survival. There is nothing worse than watching your dog die in front of you because you can't reach an after-hours vet.

An interesting rule of thumb with bloats is that 95% of bloats who walk in the vet's door will walk out again. Those who are down and require stretchering tend not to survive.

Other than that, monitor for the general joint stuff that all giant breeds are prone to, as well as congenital heart defects. Expect to pay quite a bit more for heartworm prevention and flea/tick meds than you would a smaller breed. :-P

Congratulations on doing your homework! Most people do not think so far ahead.