pcase

Hello, I would like to ask you what fans should I put at the top of my case. I was thinking about putting 2 x Noctua NF-A15 HS-PWM 140mm as exhaust at the top. Would it be better if I put them as intake? Is there a better fan than Noctua NF-A15 HS-PWM 140mm top case fan? ( And cost less than...