M.G.
I would refuse to hold his bottle while he plays. He either sits with you to drink or gets down to play.
It can take a little while to transition from the bottle to the sippy cup. I've found that dropping the bottle completely is the most successful way. You might have a couple of days that he doesn't drink much, but he should get over that.
I've always thought of the straw type cups as being for older toddlers. I've always started with the spout type cup, but if he'll drink water from it he'll drink milk.
They are stubborn, you just have to be more so!!!!!!
Good Luck, M.