How do you say May I have your attention please in Japanese?

____ o kudasai? This means (implies) "Can I please have ____ / Can you please do ____"

____ ii desu ka? This means (implies) "Is it OK that I have / do _____"

____ o negai shimasu This means (implies) "Please do me the favor of (letting me have) _____"

____ ga dekimasu ka? This one more literally means "Can (someone) do / have _____"