I had masititis and then thrush early on into breastfeeding. So expressed a lot for bout 3 full weeks.
We tried loads of bottles and teats during the time i was expressing, and i found no difference in how my baby took back to breast. He can be a little confused after dad gives him a bottle. But i just take him off and ask him to try again. He gets it right then.
However, he does have his favourite teats, which seem to be the closer to nature, by tommy tippee.
I think these bottles are great for going out with, as you can buy milk dispensers which fit inside them. This way you can still make milk up fresh when you need it, but not waste it if you don't. I breastfeed but really don't trust my boobs. I always take a formula bottle just in case so these ones are perfect. Also the teat has a whole in it, which allows the air to escape, helping to reduce wind and colic. Have found though that the teats are discolouring quickly!
Nuby teats are well liked now coz he can rub his sore gummies on the nuby bits.
Avent ones are the nicest to hold.
Health Check are a waste of money, as are Dr. Brown.
And suprisingly boots own brand are just as good as the named brands!
Hope you find one to suit. I'm sure yr baby won't struggle between the two. MW and HV recommend you don't give yr baby a bottle till breastfeeding is established properly. No mum i have spoken to has said they have had a huge prob, just little confused babies for a bit.