Those around the muzzle leaders seem to work but be aware that they do not give you nearly the control over him that you need. If he sees a squirrel or suffers some other temporary loss of sanity, it's you and that impressively thin ribbon around his muzzle and all that energy that separates both of you from devastation. So, although I am not opposed to these things, I do not think they are substitutes for good training, at least the basics, if only for safety.
The pulling is hard to tolerate and even harder to quickly train away, but start with a regular nylon collar and lead, and go for a training walk. When he pulls, stop walking until he circles back to your side. You can tap your leg to get him there, say "heel", and reward when he does. Begin walking again, and stop when he pulls. You might only get a few feet in a typical 30 minute training session.
The failure most people make in "training" is that they simply do not. They believe that saying the command is sufficient, that the dog should just know what "Wait" or "Heel" means, and since they do not yet understand the word, they cannot associate it to the behavior. That's the secret sauce in effective training, to first teach the word and associate it consistently to their behavior so when you say the word, they actually know what you mean. Being a Vizsla, they will then obey b/c, you know, they adore us. But you have to do the work to get them there, the gentle leader is a short cut that doesn't teach anything it just has this neurological influence like acupuncture. Without it, they are bananas. An educated Vizsla is a mighty fine companion. Be a good teacher and help get him there.