The Javanese greens are one subspecies of green peafowl. People say the green peafowl are quieter. They make a similar call to a regular India Blue peacock or India Blue peacock variety, but it is said their voice just doesn't travel as far. Destinduck started off with green peafowl, but generally I would say that for your first peafowl you should go with an India Blue variety. Green peafowl are endangered in the wild, and if you want pure green peafowl you have to be careful because you can easily buy impure ones. The blue and green peafowl can be bred to create a hybrid called a Spalding, and Spaldings can reproduce and so sometimes people buy a "green peafowl" when it is really just a spalding bird. It can be hard to tell the difference sometimes. So green peafowl aren't the best starter peafowl since they can be more expensive, flightier, they can't be let out of the pen, etc. Usually the cheapest peafowl variety is the India Blue.
 
The more peacocks you have, the more noise. If you are just going to be keeping one male or just a few males, I don't think it will get too noisy. When you visit a peafowl breeder during the breeding season, the only time the peacocks get loud is when one peacock calls and the other peacocks decide to start calling with him. That is when it can get noisy.
 
I hope you don't think we are trying to pick on you. Sometimes people show up in the peafowl section explaining how they have a peacock but they don't think the neighbors will like the noise so they are seriously considering getting the bird's voice removed. Other times people show up having just bought some peafowl and they have no clue how to care for them and for some reason they didn't research their basic requirements before buying them?! So sometimes we can be defensive, or I can be at least, because sometimes we get too used to dealing with people like that.  
 Anyways, we have seen some crazy things so we are quick to say "Ahhh don't do that!" haha.