They make them as 'band aids'. They're a quick fix but reschooling your horse to go well in snaffle really is a wonderful idea. Its hard, I know. My mare is very very very very VERY spirited and it took me months to get her to respond to her french link snaffle, and we're still working on it but she is so much more responsive now and overall a better ride.
The bottom line is, you need a snaffle for dressage. As for the different types, it really depends on what works for you and your horse. The best would be to try various ones and see what works the best, just remember that it will take time for you and your horse to get used to a snaffle. You might need to go back to just walk and start from there, until you can walk, halt and go from a fast walk to a slow walk easily with the snaffle. Then move onto a trot and repeat.