At first glance youd go with team gaara, but if you decide to look into it more, youd realise that team kankuro actually have a great chance of winning.
Ignoring the obvious that team gaara is the stronger team, but team kankuro have the advantage in numbers.
Now during the chunnin exams, kankuro has hinted several times that he has studied gaara's sand greatly and know his weaknesses, this could prove vital in defeating him. The key to victory for team 2 is kankuro. I believe with his information, along with sai who is also a long range fighter can cause an upset.
The two people who impressed me the most during the chunnin exams was neji and shino. In this case ill let him evade neji and allow neji to face kiba and choji instead.
Shino and lee should be interesting. Actually give the edge to shino