B16A Questions about torque

Ok, I am really thinking about buying a JDM b16a, but I was wondering about some things first. Ok, Fisrt one is stupid but the b16 is DOHC right? Second one is about getting some torque back from it. I was thinking of Modding the engine before i put it in. But I think when I have it i won’t be able to hold out that long, but anyways, What mods could I do for some torque, Will Cams, Pistons, or what. I was thinking of going all motor with really high compression pistons. Also why were talking about pistons whats the difference between dome top, flat top and all those tops they have. Sorry for so many questions, but I hope you guys can help me.