I just picked up an '05 tahoe in march with 80k miles on it. Let me say that this has been one of the most reliable and comfortable vehicles I have owned. Check your RPO codes to see what you have, or go to this site and type in your vin:
http://www.compnine.com/vid.php . I plan on a 2" lift later this year along with some bigger tires. I'm also going to do 02mdtahoe's mod of led work lights in the rear hatch so I have lighting when its open. Next mod after that is a trans temp gauge and a steering column pod to fit it in. Good luck with the truck it looks great! BTW does it have a 4.8 or 5.3?
Kevin
forgot, check out the avalanche post in here, theres info on how to run jumpers from your hi or lo headlight relay to the fog lights, DRL's or whatever you want to come on. I ran a jumper from my hi's to my fogs so that when I have the fogs on and hit my highs the fogs stay on.