Cups for Kids

When C was about 11 months old I started trying to transition him to a sippy cup.  He's 15 months old now, and uses a sippy cup for water and can drink out of a water bottle or open-topped cup if he needs to, but he refuses to drink milk out of anything but a bottle.  I'm thinking I need to get a special new cup to pique his interest.  Maybe one of these, all of which are bpa free....



lollacup, which has a weighted straw, $18



Klean Kanteen with sport cap, sippy top also available, $14.95 

Kid Basix safe sippy 2, sippy to straw bottle, $14.95

EIO kids cup, approximately $14.95.  See list of retailers

Does anyone know anything about these products or have a recommendation?