2002 Tahoe Z71 Rear End Question

[kwilki21]

I have a 2002 Tahoe Z71 with about 180,000 miles and I was driving one day and noticed that when I made a sharp turn my car would occasionally make a small popping noise. Over time this small popping noise turned into a loud jolting noise to the point it seemed the car seemed unsafe to drive. I quickly drove the vehicle to my dad's performance shop for him to take a look at it. He pulled off the casing on the rear end and metal pieces and shavings were in the fluid. He then said the rear end would have to be replaced. My dad has all of the tools and space to replace this, I just need to know which rear end I should buy or what options I have. Basically I'm asking what I should look for in a junkyard or on ebay, or if I can buy new or factory refurbished or what is exactly needed for my tahoe. Thanks for all your help and I will answer any questions.