The size of the hotspot depends mostly on the size of the light source (which we don't know for these LEP lights, but they are probably all very similar in this regard) and the focal length of the lens. The focal length is basically the distance between the lens and the light source. So your best bet in determining the size of the hotspot is to try the light with the shortest focal length. I realize that finding out this value is somewhat difficult.

In reality focal length is not completely indepedent of the lens diameter. Lenses with smaller diameters allow for shorter focal lengths. So just trying the light with the smallest lens diameter might just be all that is needed. You can find this out by estimating the the thickness of the bezel based on pictures of the light, multiplying it by 2 and subtracting this value from the diameter of the flashlights head (this value is usually given by the manufacturer).