Go the clinic and learn
Any instruction, if you're trying to teach yourself, is better than nothing. I think it's harder to heel than head, my best friend would tell you the opposite.
At the beginning levels, most horses can do 'both ends' if they're broke enough to be solid, score, track a cow, and take the jerk. Once you get more competitive, then you generally want a designated head horse or heel horse. Also bear in mind that if you're doing a lot of roping, your competition horse is not the horse you practice on every day. Those are two different mind-sets on your horses, and you need different horses for different things, and most of your practice should be scoring, slow runs, and breakaway hondos to save your horses and stock.
I agree that if you want to learn tie-down roping, it's harder to go from heading to that than from heeling to that. If you want to do both with the same horse, stick to heeling rather than heading. A head horse has to be fast and rangy and take a big jerk, then turn and face. Most are on the 'hot' side of the temperament spectrum, but they've got to be honest. Your heel and calf horses need to track and then stop clean and straight, then work the rope. They don't need to be as fast out of the box at the lower levels, and you can get by with a less athletic horse than needed for a head horse on big steers. Not the same thing as a head horse at all.