Feeding bottle teats advice and recommendations

Hi my LO is 6weeks and feeding on 120ml every 4h. However he takes close to 45min I’m finishing his milk with using Hegen and Pigeon bottle. I tried using Philip Avent and he can finish within 20mins but it’s giving him a lot of gas so I don’t really fancy. I heard that UK brand teat is faster flowing than Asia brand teat. Any recommendations on UK brand bottle that can give LO a more effortlessly drinking session and doesn’t give him lots of gas? Also what is the ideal drinking time for 6 weeks old?