What should I look for when choosing faux tin ceiling tiles?
After searching for a while I came across TinCeilingXpress.com They offered a 5 panel sample package which allowed me to pick 5 tiles to see what I liked best. They are reasonably priced and I found they were quick at shipping and the products came well packaged. At ~$7.00 a tile I ended up buying these tiles:

 

I have been pleased with how easy they were to put up and how great it looks. My biggest gripe is how sharp the tiles are. I would highly recommend some gloves when installing.

Best of luck!