If you have to choose between the two, Life Orb is the better option. This is because Talonflame isn't really good when he is choice-locked, as Talonflame has many great status moves you will want to use, such as Roost and Taunt.
However, the best item to give Talonflame is Leftovers. Talonflame's stats might say otherwise, but Talonflame is a viable defensive Pokémon thanks to moves like Will-O-Wisp and best of all, priority Roost. In addition, Leftovers helps to cancel out Brave Bird recoil damage. Life Orb just adds more recoil damage, which cripples Talonflame's ability to survive.
If you want an alternative for an offensive set, Sharp Beak is surprisingly a good choice. As I said before, Life Orb does recoil damage, which Talonflame doesn't like. Sharp Beak boosts Brave Bird, which is its main attacking move without inflicting additional damage to itself. However, Sharp Beak is pretty underwhelming, and I prefer either Leftovers or nothing; in this case you would give it Acrobatics.
