Hi, sorry I'm just getting back now. Things have been crazy with work over here

I actually just posted on another thread about how I got Dylan to take a bottle of ebm around 10mo old, and how we transitioned from the ebm to soy. I'll copy and paste everything here, and let me know if you have any questions

So, what we did. We had experimented with different bottles and nipples also, trying to find one that he liked. Of course, he rejected all of them. I was in a bit of a panic, as I was returning to work in less than 2 months and he *had* to be drinking something other than me! We went to see his doctor, and he said to pick a bottle and stick with it for a while, at least a week if not longer. He said that bottle feeding is so foreign to breastfed babies that changing bottles every couple of days (which was what I was doing) was really counter productive as it didn't allow my ds time to get used to any one - so of course he was rejecting them all! So we chose the playtex drop ins for a couple of reasons:
- it was the bottle he had rejected the least (if that makes any sense)
- the nipples were wider and slightly more like bfing as pp said
- the nipples were available in a variable flow (very important for us, even slow flow nipples allow milk to just drip into ds' mouth and he didn't like that, with variable flow the harder he sucked the more he got, but if he didn't suck he didn't get anything - like bfing)
- they had a collapsible bag which created a vacuum so there was always milk in the nipple, you never had to hold it the *right* way (this was also very important, as ds did NOT want me to hold a bottle for him, the vacuum allowed him to hold it himself in any position he wanted, even while crawling)
The other piece of advice my doctor gave was to choose one feeding to replace at a time. Once he was taking one feeding well from the bottle/cup, then drop the next. At the time, ds was nursing at 7, 11, 2/230 (before 2nd nap because of long A times) and before bed. We started with the 11am feed. I put him in his bouncy chair (did NOT want me to hold him in the early days) in front of the TV (baby einstein, he did a bit better when distracted) and gave him a small bottle (about 3/4oz) of ebm. (We had tried formula and he rejected it outright, so I pumped). I would let him play with the bottle, chew on the nipple, etc - as long as he wasn't upset, I left him to it. I would stroke his head or rub his legs too. If he dropped the bottle, I would hand it back casually and if he didn't want it that was fine. If he got fussy I would take him out of his chair and let him play. I continued to casually offer the bottle (just handing it to him while he was playing), but with no pressure. I fed him his normal lunch around 1230, and tried the bouncy chair/TV bottle one more time around 1/130. Once he refused it then, I didn't offer it any more and breastfed at our normal time. The first day I think he took a couple of sips, but over the next couple of weeks he started taking an oz, then two, then drinking the whole bottle! Once he was drinking well (about 4/5oz consistently) we moved to the 2pm feed. This one went much more quickly as he was already drinking well from the bottle.
Then we made the transition to soy milk for his day feed (much later, we didn't do this until about 15mo, I just kept pumping for bottles of ebm) and I did it gradually too:
Week 1: 4oz ebm, 1oz soy
Week 2: 3oz ebm, 2oz soy
Week 3: 2.5oz ebm, 2.5oz soy
Week 4: 2oz ebm, 3oz soy
Week 5: 1oz ebm, 4oz soy
Week 6: all soy
We didn't have any problems with rejection along the way, so this worked quite well for us

You could go more quickly if you needed to, or more gradually if you encounter rejection so this is a nice way to transition.