bits stronger than a snaffle but suitable for showing

[inkydoodles]

i have a welsh d, 5 year old he is in a plain jointed snaffle but need something a little stronger as he hard to stop.
also has a flash to keep his mouth shut but he gets very annoyed and agitated with it.
i need a bit suitable for showing and jumping any tack or bit suggestions ?

 

[wonderhorse11]

this would probably get more answers in the new lounge and sorry i dont know much about bits