How much item level we need for the new content?

[MistakeNot]

You can also do Orbonne Monestary to try and get a piece of gear from it. Running all three 24-mans give you tokens to trade in for upgrade pieces for left and right side, so you can get easy i400 gear. The weapon upgrade will probably be added soon, too (I don’t think they added it this last patch... can’t remember).

If you have good enough gear to even enter Orbonne Monastery (i365 required) then you already have good enough gear to finish the MSQ, as well as good enough gear to enter all other non-Extreme/non-Savage content in the game.
In other words, if you can run Orbonne Monastery then you no longer need to grind for gear unless you really want to do the hardcore content.