Haha, Kevin is starting to regret coming over here. Just kidding! So many questions it's hard to keep up ya know. But that's why these places are great.
Jay, you are really digging too deep regarding your chest. It sounds like you are a beginner. You should not be worrying so much about the little nuances of the weight room. Worry about building a balanced weight training regiment and more importantly and harder in my opinion, work on creating proper eating habits.
Chest pressing, does not matter incline, decline, or flat is mainly hitting your pecs. Depending on the angle, you are going to stress different parts of your pectorals more than others. However, each works the entire chest. Along with the pecs, and why the chest press (bench) is a compound exercise, you are also working your triceps and your anterior deltoids.
The questions you are asking is making believe that you need help with your entire routine. What exactly are you doing right now for weight training?