My DS is 4 months old weighs 9kgs and has wind ...

My DS is 4 months old weighs 9kgs and has wind problems! Up until yesterday he was exclusively breastfed! He has 2 teeth down the bottom which he has decided to start biting me with ouch!! I have decided to wean him onto formula as he hurts me so much just his sucking is so strong. I breastfed my eldest Ds for 12.5 months but this time is so different! I have no idea about formulas which one to give him cause he so much wind which teats to use to prevent him sucking air! I know he gulps my milk and I have tried everything to try and prevent this, nothing works or it does for a while then stops he is on infants friend used infacol for a while but didn't help! When he was really little he had donnalix colic relief, he doesn't seem to suffer from colic as such anymore just lots of farting!! I am really looking for anyone who has had the same problems or knows of anything I can do with formulas and teats! Thanks in advance!!