From an ARR point of view, the later story quests required ilevel 90 gear, which was 40 levels higher then level 50 gear. It's much the same thing this time.

The Law gear and the upgrade materials to get them to ilevel 180 are available for Centurio Seals ... I used this method to get most of the gear that I still didn't have. The Sky Pirate gear (185) can be purchased on the Market Board. It can be expensive, but if you have gil it'll cut down the time.

You can also get Esoterics gear from the daily trial/dungeons, using the Seals for the stuff you haven't got just yet.