I am currently using a Playtex nurser with the original silicone natural action teat. I need to get some new teats, ideally with a faster flow rate. Anyone know if the silicone teats do come in a 6 months+ version? I only found latex teats for 6 months+ in my local chemist and my son is NOT impressed with them. I have looked at a few mail order websites but they're not very clear.