Just got the trading card in today from PrimoPrint and they are beyond my expectations. The 16 pt paper has a nice thickness, and the gloss is lovely. (I usually prefer matte but thought the gloss would be a good fit for these cards. Have to still mess around with some readability issues (it's hard to pack in a lot of info on the back of a 2.5x3.5 card. Bell Centennial is a good choice, perhaps, it is used in the phone book so it is super readable at small point sizes.
Will be checking in at various stages of this labor of love.