Question concerning Item Level Requirement and Area Level

Hi,

Is there a way to know what area must be farmed in order to find a given item in its Normal, Magic or Rare quality ?

For example :

Let's say I want to find a white Sledgehammer.
This item requires Level 17 (http://pathofexile.gamepedia.com/Sledgehammer).
And there are two Level 17 areas in the game, Normal Crossroads and Normal Den (http://pathofexile.gamepedia.com/Zone_Levels).

Am I right to assume I have the best chance to find this item in these areas ?

17 is the minimum level requirement a monster needs to drop a sledgehammer.

Rare monster: lvl 15+ zone
Magic monster: lvl 16+ zone
Normal monster: lvl 17+ zone.

With higher levels, more and more base items will be added, reducing the overall chance for a sledgehammer.

I'd pick a zone between 17 and 20 that has high monster density and can easily be farmed.

sorry to jump on likr this.

but i'm curious, is this some example how "DropLevel" works in item filter..?

Thank you Peterlerock for your answer !