it took us quite a while to get the hang of the sippy, but i never gave him any in a bottle, because for the same reasons as you i did not want to stick with bottles any longer than necessary. We had most success with the basic tommee tippee one (where theres no valve etc!) til he could do it himself. Now at 14 months, i have valves in nearly all the sippys, as they get chucked on the floor so often.
Persevere with the sippy, or try open cup, if you want to get some water actually in him. We did water drinking only really for practice at this age, so it didnt matter to me that most of the water dribbled back out at the times he actually sucked some!
I would try chamomile in the early evening maybe? or before a nap?