With a push up the closer your hands are together the more you will call upon your triceps to assist, just as in a flat bench workout, close grip bench = triceps.
As Standapart mentioned focus on the main chest exercises, incline bench and flat bench. Opposing muscle groups are important to proper development, your back(lats as mentioned) helps your chest/abs and vice versa.
If you need to gain mass to build that chest, look to your core strength exercises to help gain that mass (deadlift / squat).
The actual amount of weight you lift will not determine your chest size/rip. Everyone is different and you need to work with your body type and capabilities. As long as you are lifting heavy weights for you, you should see gains in mass (if your diet is accompanying it), if you just need to tone up a little you can look to more reps/set.
Hope that helps.