I sj, xc my horse in a 3 ring french link gag, which obv isnt dressage legal. he has responded very well to a myler bit, quite expensive to buy tho.

just try lots of different ones and see what works

 I love irish sport horses i have one :) Mine is strong too but has a bad mouth/teeth as he wasnt looked after very well were we got him from anyway i use a egg but snaffle it put pressure on them when you pull but only anought to keep them under control hope i helped

Thanks very much for the answers but ive got her in a hanging cheek and shes doing great. She does still hold her head high but im presuming that this is due to the lack of suppleness in her neck. I will continue to school her and hopefully she will get there, thanks :)