if your palm is bigger or equivalent to your face, get Corsair M65.

If your palm is normal size but palm grip style, get Razer DeathAdder Black

I saw a vid where a few CS:Go pro players used DA 2013, some used SS Sensei. Try testing them on your hand first. DA has hyper-responsive buttons, so it doesnt take alot of force to click. I've tried the DA for a few mins and it the button or clicks were just too soft for me. I've also heard some customer reviews saying the buttons doesnt last long and stuff. The M65 has a dedicated sniper button, but u i think u can change it to something else. U can also adjust the weight. Check customer reviews before buying it. Newegg, Amazon etc. Cuz some webistes are paid to talk good things bout certain brands. And test the mouse before u buy. BUT, i do not own any of these, ask people who owns them, im just giving my opinion