Hardness isn't going to come from a movement...
That said, don't do all three. That's wasteful. Focus on increasing your flat and incline bench pressing (mainly flat, learn proper form first) poundages. As one goes up, in general, so will the others. There's going to be some degree of carryover. That, of course, is looking at it from a strength perspective.
In terms of size, well, I feel strength is going to lead you to it anyway. This isn't far from the truth. Progression in load, accompanied by proper eating habits (i.e., excess caloric intake) will lead to muscle growth.
Regarding hitting "all angles" of the chest, you have pectoral muscles. Major and minor, sternal and clavicular. The flat bench press, contrary to popular belief, utilizes both of these to their maximum degree. The problem is, people refuse to believe this, and feel incline emphasizes the clavicular, "or upper chest", muscle more. What it does is, it take the emphasis off the sternal head of the chest, which allows the top to grow in at a faster rate than the bottom would, were one using a flat bench press.
I would almost put incline as touch-up work. Focus on your flat bench. It will give you "gladiator pecs". You'll grow. You'll be functionally stronger. Work on incline bench once a week, flat bench twice. That's just a recommendation, but you can find something else to work well, I'm sure. Eat enough calories to sustain muscle growth. You'll wind up bigger. Don't worry about anything else, and take it one step at a time.
As a reminder, please check the bench press sticky at the top of the powerlifting forum, to make certain you know how to bench properly. We don't need another one succumbing to a rotator cuff injury or anything.