Quall is right. You should go get Xecuter 3 or 2.6b if you have the knowledge so solder yourself or can have someone else to do it for you. They are very good modchips!
If you can't solder and still wants to do it yourself you can get Xenium S.P.ICE. These chips are solderfree (can be soldered too), has the same features as Xecuter 3. Only difference is that Xeceuter 3 is a little newer and better general repuation. The price is different too, making the Xenium chip cheaper.
Also do some reading on
www.xbox-scene.com and you will get enough knowledge about what and how to do/get to your xbox.
Good luck!