L.M.
There is a cup called "Nuby" that has a very soft spout, which might feel more like a bottle.
We basically just stopped giving the bottle and got rid of them. My daughter transitioned with those soft spout cups, but my son wanted a straw, or even to drink straight from the cup! So you can try that, as well... just to give him the idea that milk comes from other places than the bottle.
My son (2 1/2) still doesn't like to drink from a sippy cup, and walks around with an open cup and straw. We get a lot of spills... but c'est la vie.
Good luck.