You could try the Playtex Ventaire bottle which are their resuable offering - it has a naturalshape teat but its not as soft as the disposable system one - sadly the Playtex teats only work with the Playtex bottles - having been through this many times.
Note for Stephanie - Playtex the bra people and the bottle people were linked once upon a time but when they separated they agreed to keep the brand name - apparently because people recognised it - I asked the same question!!
Has anyone ever found any other bottles that the Playtex teats will fit onto? My ds has refused all attempts to try other types of teats and wondered if I could find a bottle they would fit rather than keep having to buy liners.