It depends on the game mode. If you're playing basic chest items, the swordsman kit or iron golem kit is the way to go. I don't play on normal or overpowered items so I'm not really sure what to suggest in that regards.
For basic chests, I would recommend using the swordsman kit, as it is very effective against other players, if you're good at pvp.
For normal and OP chests, I would recommend using speed II kit, because it can help you sometimes to make more combos and kill others more "faster".