i want to know what pully is the best and would give me the most power. I dont want one of those piggy back one, i know that

 

The ASP pulleys are a popular choice.

 

There are a lot better mods to do than pulleys. With our waterpump not being belt driven the gains from one are minimal and some guys have charging issues with them. IMO pick another mod.
They are however good for say road racing and can help keep the PS from overheating under use like that.