What are the fastest longboard wheels?

I have some friends and i that are gonna arrange a downhill race session soon, i dont think the road will be too curvy.. and i was wondering what are some very fast wheels that will accelerate fast and hold speed well. Im currently using lemon big zigs (75mm 83a, which are probably worn down some mm's). I am kinda trying to keep away form things like the centrax cause it jsut looks too meaty... like it will grip so much that any form of slide or fast acceleration would be hard. That giant contact patch doesnt seem efficiant for speed... but maybe im just undereducated haha :)