I always start horses in a french link loose ring. Its gentle, and fits the contours of most horse's mouths better. Just keep in mind that every horse is different, and just because one bit worked and/or fit in one horses mouth doesn't mean that it is the bit for you and your horse. Definitely start with something very gentle, and work from there. Personally I am not a huge fan of hackamores, or bitless bridles, but I have used hackamores before, and I did ride a horse for a while who didn't do so well in a bit, so I started riding him in a jumping hackamore, and he did awesome.