I'd do a lot of research before delving into that endeavor. All I've ever heard about that breed is negative, behavior wise. DH says they are a flight or fight breed. To quote him "You get in the pasture with one of them. They will either jump every fence in the county to get away from you or do anything in the world to hunt you down."
Couple things to consider. Are you set up for them? Wire fencing is not going to contain them. How are you going to market them? In our area you wouldn't get anything for them at the stockyards. And no one would want to buy a purebred around here. You'd have trouble giving one away.
I am curious. Where did you get that they were gentle? Every cattle man I've ever talked to cringe at the thought of a mean ol' bram.
I've met a group of people at out local fair that show Brahmans, and I was lucky enough to help show one of them. When I was handling the heifer, she was extremely calm and went wherever I wanted her to. Much like some dairy cows.
My friend has worked on cattle stations in Australia where all the run are Brahman cattle. Some that have been handled from birth are super tame, like any cow, but as a whole the breed in my opinion is hard to work, and mean!
We see a few around here because with the drought up north they were dirt cheep however they dont sell as well as the european based breeds and have a reputation for being hard to handle .I would do some more homework and really check out the breed before you buy one .