So I was thinking about which slot to choose as non-tier. Firstly, the tier gloves and pants are perfectly itemized, so we should probably drop them from consideration. For head, pretty much everything has crit, so there is no real advantage to going non-tier. That just leaves chest and shoulders.
Chest: There is, currently, no 277 leather that has spir/haste on it. However there is a 264 with spir/haste
http://www.wowhead.com/?item=50973and a 264/277 cloth (good luck) that has spir/haste
http://www.wowhead.com/?item=50717Shoulder: There is a 264/277 leather that has spir/haste
http://www.wowhead.com/?item=50715Right now, I would lean towards the using the chest as non-tier. The leather can be bought with badges and gives more haste than its shoulder counterpart (108 vs. 74). A nice list of gear choices can be found at:
http://www.plusheal.com/viewtopic.php?f=5&t=5073 