You can buy Panaflos with both 3 pin and 4 pin tails. There is no standard. But most commonly they come with a 2 pin connector that will fit on a 3 pin connector when one of the polarity tabs is trimmed off.
In my testing a Zalman 92 mm fan in silent mode (5 v) is 10 db quieter then a Panaflo 80 mm L fan at 12 volts. The Zalman at 7 volts is 3 db quieter then a Panaflo at 12 v. This is measured with an SPL meter at 4 inches distance, perpendicular to the axis, in free air, sample size 5 of each.