Okay, after extensive testing, here are the types of materials needed for the supply order quests: leather, bronze, steel, *iron, burlap, cotton, hemp, wool, satin, *wood, *copper

* are the cheapest 3 materials to start with and easiest to make a profit using

As noted in above post, the price you get for the supply order is dependent on your char level, so even at level 1, with a lot of perseverance you can turn a profit if you just stick to wood or copper items. This will also depend on your charisma/appraise levels as well. Higher levels will give you more of a cash reward, so that makes it easier to profit plus higher levels give you more exp as well.