The design for a cloud chamber is rather simple, and many factors can be changed without producing different results. There is one curious point that I've stumbled upon, though: The type of alcohol vapor used. I've read about methanol, ethyl alcohol, and isospropyl alcohol.
Will any of these choices produce different particle tracks? The factors I'm considering include the length of time the track exists for before it fades and the clarity of the track (i.e. opacity/transparency relative to the rest of the vapor).