while I like the excursion diesel angle, $30k is too much for a daily driver that will tow a couple times a month. . .
Also, have you sat in one of those? It's like a bus!!
a friend tows around 6500lbs of boat with zero issues in a denali. Before that he used a normal yukon. with a 5.7 or 6 and a tow package you shouldnt have any problems with a tahoe.