It depends on you.
I cant help you in what type of implant is best for your brachiosaurus because i am not playing your game.
It depends on how you use your brachiosaurus. It also depends on techs too. I will just suggest in what type of implant you would like to have for brachiosaurus.
Brachiosaurus:-
It has best health than any other dinos, because of it toughness,robust it takes less damage. But it is very slow.
So I suggest you to get
1] 1)Strength 2)recovery 3)endurance (no vital becoz has good health, no armor becoz it takes less damage)
2] 1)Vital 2)Armor 3)Strength (will increase health, will take least damage,Strength implant makes you a lot more difficult to kill)
3] 1)Recovery 2)Endurance 3)Armor
Recovery implant and Endurance implant is the best for brachiosaurus