i would personally rather have brahman cows and a hereford bull. i like brahmans and always have. they are very well adapted to my area. however, they are very expensive. also they can be temperamental if mishandled. however they are excellent mothers and very protective of their calves and always wean a great calf. heat tolerant, disease and insect resistant, longevity, very little calving problems, etc. ive heard that brahman cows dont really like other breed bulls, but i dont know how true that is. if hes the only bull around she cant resist his advances.
with hereford cows, the biggest PRO i see is that you can get good hereford cows for cheap and a good brahman bull for cheap! its probably easier to get hereford cows too. if you get good milkers they will wean a great calf and supposedly herefords are as gentle as they come? like all breeds, some brahman bulls may throw some big calves and herefords may have more calving difficulty if you dont pay attention to whats going on.
Another thing to take into consideration is that you might change your mind or want to try something different down the road. if you have brahman cows you can breed them to angus, hereford, simmental, etc but all the calves with be eared. if you have hereford cows you can breed to an angus, brangus, simmental, etc.
in my case, it would make more sense for me to get brahman cows since i have other eared cattle that i could use a hereford bull on. i wouldnt to use a brahman bull on already eared cows.
either way will work equally as well, its just up to your preference.