I've never heard of barefoot bridles, but I use a Libby's Scawbrig and am very pleased with it - horse goes very nicely in it and it is not the least bit severe, as it acts all on nose, under chin, sides of face (a little) and poll. Hope this is of some help.
Said the little eohippus, "I´m going to be a HORSE"
My old gal couldn't tolerate a bit, but went nicely in a good old-fashioned English Hackamore. However, she would take the p*** in a scawbrig/kineton. The hackamore gave just that extra tiny amount of control that made her respect it.
I would suggest that you at least *start* your filly in a bit before going bitless (if you haven't already done so), as so many disciplines don't accept bitless bridles of any kind. Then you won't be limited to what you can do later on, and she will find it much less of a shock that doing it the other way round.
Remember though that a bitless bridle is not *necessarily* kinder than a bitted one - it depends where the pressure is placed and how much is exerted by the bridle/rider in combination. And it is definitely not kinder to your horse to ride them in a bridle which doesn't give you 100% control in an emergency - and emergencies can happen with even the sweetest youngster