Hoof knives come in left and right handed models, and come in many levels of quality. A midlevel hoof knife is more than adequate for the typical horse owner. The key to the use of a hoof knife is keeping it sharp. This is a tricky skill.
My recommendation is that you have your farrier keep it sharp for you so that it is sharp when you need it. A dull hoof knife is worse than no hoof knife at all! Do not use a hoof knife to pick out a hoof as it will dull the blade quickly. Use a pick for that.