Depending on the breed, you can tell roosters by their comb, but you can always tell them by their tail feathers. The males are also brighter and puffier than females.
I wish I had some suggestion to make the rooster shut up, but dinner sounds like the plan of choice. Actually, you might ask your neighbor if he wants to sell the rooster and give it to someone who lives far, far away.
I also don't believe people are allowed to let their chickens roam all over the neighborhood. For one thing, they are very dirty creatures.
I wish you the best on your delimma. If by chance you buy the rooster and need instructions on how to clean it for dinner, send me a pm and I'll tell you. (It's a bit graphic for a forum.) Ick.
Jan