There are a number of Mantis styles in NYC - Carl Albright teaches 7 Star mantis - his school is known for producing good fighters. I train in 7 star praying mantis and can attest to it's speed. If you want to see mantis speed in action, search YouTube for Brendan Lai.
Regardless, like mentioned previously, learning and utilizing speed takes place independently from style. You can learn it from boxing, judo, jiu-jitsu, wing chun, eagle claw, or mantis. Just find a good teacher.
Speaking of good teachers, I think the Eagle Claw (ying jow pai) school is Leung Shum's school. He is just about the most amazing person I have ever had the priveledge of learning from. I doubt that you'll get training from Master Shum personally, but his students are top notch.