D.K.
Hi, I never bottle fed so my advice may not be exactly what you're looking for, but when my sons were ready for liquids other than breastmilk, I just started them straight out on regular cups. It cuts out a second transition later on. It's messy at first, but you can minimize that by just putting a tiny amount of the beverage in the cup at a time and by buying cups that are small enough for them to easily handle. My boys were each about 9-10 months old when they learned to drink from a regular cup. You could give it a shot anyways, what have you got to lose? :)