Sounds like you're going to do solely calisthenics from what I can gather. I'm actually currently undergoing a gain phase myself. I'm trying to gain as much as I can for maximum power right now, then cut down afterwards for speed.
I can tell you right now from my experience calisthenics will help you out but won't be nearly as effective as lifting weights and doing power exercises like benches, squats, deadlifts, etc.
I know it's hard to start but if you will the rewards are assured. I am currently in the beginning of my 2nd month of my lifting routine and I have had huge results. The key is to switch up your workouts constantly so your muscles will be constantly growing.
Of course I do calisthenics too. But I keep it to a low amount as possible because these exercises like pushups burn too many calories and my gain will be decreased. I'm actually reducing my cardio exercises as well, but I will resume them as soon as my gains are complete.
Now the good thing about calisthenics like pushups is that it is harder to lose your results, meaning it will take longer for you to lose what you gained during pushup training over a long period of time. When you lift weights you can start seeing losses in strength if you stop lifting in as little 3-4 weeks.
Pullups are great too, but if you are serious about gaining, especially for something like sanda, I recommend signing up to a local gym to get the necessary gains at least for a while. But remember to always maintain what you got by consistently working out however you choose.