Teats on bottles - closest to breast?

My LO is just 3wks old... We have recently started combi feeding (mainly expressing and 1-2 ff per day).. We were exc breastfeeding but we were keen to share feeding. Anyway bearing in mind hes used to the breast (ie having to work a bit harder than with bottles), we find that now with bottles he is getting milk too quickly. Ie flow is too fast perhaps. He coughs n splutters a lot, and loses a lot round his mouth/chin.

We are using TT closer to nature bottles as i thought these were best and closest to the real thing, but he ends up gagging a lot, spitting some out and generally wasting a lot (its not the waste i mind of course just dont want to assume hes taking say 4oz but half of that isnt taken as it comes out his mouth/down chin or is coughed/choked up).

Are there any much smaller teats with slower flow? That are more like breastfeeding ?