The itemtype.dat file (..\ini\itemtype.dat) stores all the items display data for the items.
The MapItemIcon.ani file (..\ani\MapItemIcon.ani) maps each item to an icon, or icons for animation, these icons are either stored in the data.wdf file or in the ..data\MapItemIcon directory.
The icons are normally .dds files.
The icons that are stored in the data.wdf may be extracted with several apps. Many can be found on elitepvpers.
So if you are thinking of creating a new set of icons for conquer, yes it is possible.
Since we are on the topic i am busy creating an application that allows you to modify item names and icons to anything you want, Its still in the making but this is what i have so far. It does not save the items yet as im still testing it.