You might be stuck with the enclosed above the coronet band type of boots until you get more of a barefoot shape. The problem with them is that they sometimes rub, especially on long/fast rides like endurance. But as a transition, it may be a good start. Another option that might work is Easyboot Epics. They aren't designed to fit that shape necessarily, but that is what I used while transitioning my horses from shoes to barefoot, during the awkward stages where their feet weren't quite right and I didn't want to spend money on nice boots that wouldn't fit in a few months... I found the Epics will tolerate a lot in terms of poor fit: flares, wrong size, etc. I used Epics on a horse that probably should have had the next size down, and I made them work fine by using athletic tape around the hoof a few times before applying the boot (like the Glove users sometimes do for a tighter fit). Worked like a charm for a short term solution. Now their hooves are transitioned and they have Renegades/Vipers, but I don't think they would work as well on the upright shape.