Funding, subpoena power and publicity would be necessary in order to get anywhere. It might be possible to get funding through a massive internet appeal. But, the MSM likely would totally ignore public hearings and subsequent findings so that a large part of the citizenry would never hear about the evidence presented and conclusions drawn. Without subpoena power, the mouths of those who could fill in some of the missing pieces of the 9/11 puzzle would be tightly clamped. (Even with subpoena power Congress has been stonewalled recently.)
Now, if we could grant ourselves waterboarding and extraordinary rendition powers, it might be possible to fill up Gitmo.