The one with pictures in the first post is definitely a male.
You're right, he's got a large red comb.
And crowing is also a good sign of him being male
But he's also started to grow some skinny, pointy saddle feathers (they grow from his back, just in front of the tail, and when they finish growing they will be long and hang down to both sides). Those are normal for a rooster, but not for a hen.
Also his coloring (mostly red, with a black breast) is common in roosters, but almost never happens in hens.