Nightmare with BFree teats - any advice please?

[CJ1836]

Hi
My 8 week old is using Bfree bottles which seem fine but am having a mare with the teats. As she is on Infant gaviscon which I am sure thickens the milk, she feeds REALLY slowly so I got some of the next stage 3-6 month teats which are way too fast for her. DOes anyone have any other suggestions re teats or bottles I can try which are similar to the Bfree in helping reduce colic?
Many thanks
CJ1836

[CJ1836]

Do the teats fit ok then? That is what I was thinking about doing.