We used the Tommee Tippee one,it was good for changing from breast to bottle with my last two.One was 3 months,one 1 month when changing,you might find a 7 month old harder to change.My now 6 year old never had a bottle,she refused to take one at all.She went straight from breast to cup.She was taking juice from a cup so I just put formula in the cup and she would drink it like that.When she started on the formula I mixed it first part breastmilk part formula,to introduce the new taste gradually.
Good luck.