If you are looking to support the tendons and joints more - smb's are the way to go. They are expensive, but if you are going for an smb boot, get either the professional choice or classic equine brand. Although they are the most expensive, they are the best quality. You would most likely need a size large. Now, just remember, don't leave them on for more than 2 hours at a time, because they trap heat. And if you are worried about swelling, I would take them off more frequently to check for swelling.