Do all 4.8is have sport package?

[taosx5]

I have had an 03 4.4 since new. It is my wife's EDD and it has been a great ride. This leads me to my search of an 04 thru 06 4.8is. I have asked several dealers, and searched many other sources and no one has been able to answer these two questions. I have tried searching the old forums and I think I have the answer but can anyone tell me straight out?
1) do all 04 thru 06 4.8is have the sport package?
2) do they all have the air (self leveling) suspension and is it part of the sport package?
I saw a 4.8(i) a few days ago and assumed it was an 07. It was not equipped with the off set 20" wheels and tires so I am also assuming that the (i) means it does not have sport package. Am I correct?

Are there any things to look out for when purchasing a used 4.8is? If it does not come with an extended warranty, does anyone reccomend any independent insurers that have a good reputation? If the carfax shows no issues or repeat service related problems, does that indicate a fairly trouble free car? I found one that had been in for service multiple times for 1) replacement of wiper blades, 2) check system electronics, 3) tire balance issues. I thought item 2 might be something but multiple issues with wiper blades and tire balancing I found to be a little strange.

Thank you all in advance for any input.
~doug