You're also going to need the setup tools and a dial indicator. Getting the pinion depth and backlash set correctly will have a lot to do with how noisy the gears are, and how long they last.... As for selecting the best gear, depends a lot on how the car is used. A cheap gear set will not live long behind a big horse engine.....

You probably already knew that, just thought I'd mention it in case some thought changing gears was just a bolt in and go deal......