I bought a Yukon Denali last month. I agree with the last couple replies in that the dealers really aren't that helpful as far as searching for the car or truck you want. I used GM buypower, but found that inventory changed so quickly that a call to confirm was required. If you call the dealer and confirm they have the one you want, you have to be ready to commit or it will be gone. Some dealers in the Phoenix area were moving a dozen Denalis in a weekend.
You will not be disappointed. The 6.0 is so much stronger than the 5.3.....all in a half ton chassis!