DB - are you affiliated with any local Arabian groups, associations, or breed associations to find an appropriate trainer reference? If showing Flame is the goal, seems you definitely need a trainer who is familiar with the nuances of the Arabian show world.
That said, my barn owner takes in a few training horses here and there. She's a dressage enthusiast, but a good foundation on a horse is a good foundation for any direction, IMO. She owns an Andalusian stallion and works with a little gray Arab stallion, among others. http://geminifarmstx.com/training.html
CC - are you a seamstress or is this costume making idea a seat of your pants experiment? I hope you share pictures of the final outcome!