Starting any horse, no matter what the final discipline the horse will be used for, a snaffle should always be the starting point.
The mouthpiece doesn't matter, as long as it's smooth (no twists).
As the horse progresses and starts learning self and proper carriage, a curb with a similar mouthpiece as the snaffle had is always good, with short, curved shanks.
Then, in pleasure, usually low ports come into play once the horse is truly finished off, and can be ridden soley on leg cues with a draped rein.
"You're just as sane as I am."~Luna Lovegood.