Well, there's the quill-type and the threadless-type, so you'll need a threadless headset and a threadless stem. There are tons of them out there, so you have plenty to choose from. They come in either 1" or 1 1/8" sizes, so be sure you get the right one.
__________________
It is my belief that every person in this world has something to teach, and everything to learn.
In memory of Jim Price (aka. sydney) ...