Charlene1985 My suggestion is to contact the original owners (if you can get a return call) and find out what bit they used on him.
I did start my young girls in a Cooks bit less, then to a french link d ring but my ultimate goal is to put them in a curb bit.
Those who think its the bit that makes a hard mouth are wrong. Its hard hands. Any
bit can make a hard mouth even a piece of rope.
Go with what works with your horse and don't worry about what others say.
I used to ride in an Imus comfort bit (which is indeed a shanked bit) until I noticed a separation at the center that could be a pinch point. I think Ms. Imus is aware of the quality issue with them and is working on it.
In the mean time I have gone back to my old standby, A Myler that looks like this. I think its a Lynn McKenzie series bit.
Just an FYI. As far as hard mouth vs soft mouth. The action of the bit in the mouth is determined by the mechanics of the bit. Some rely on tongue pressure some on bar pressure some on a combination of tongue bars, poll, nose and curb. You want to start off easy thus the direct reining pressure of the snaffle and bitless. A finished horse relies less on the bit pressure and more on the other cues like leg, seat, voice etc.
If you want to start refining the motions you start a bit that has seperate side action. I want I finished horse to neck rein. I find the curb bit is better at communicating that action.
Sorry I'm rambling now
My advice to you is to Do what works for you.
Sometimes we (at least me) have a tendency to over think things and listen to too much advise rather than just working it out ourselves. No one can tell you whats going to work with you and your horse. That's the reason there are so many bits choices
Not all horses can handle a snaffle bit because of the nut cracker action on the tongue. Others can't handle a curb.
PS All of our kids are barefoot. We use hoof-boots on those rare occasions when the terrain is to rough.