I use PT/PT2/PT2mini single coil heads in my Aerotank all the time without gurgling or leaking. All you need to do is add a second grommet on top of the first (not inverted) and it makes it the same height as an Aerotank/PT3 dual coil head. To answer your other question, the Aerotank/PT3 dual coil heads will not fit in a PT/PT2/PT2mini because of the increased height of the dual coil head.
Sorry if the picture is a little fuzzy, but that's a rebuilt PT2 single coil head w/ an extra grommet for my Aerotank on the right, and a stock Aerotank dual coil head on the left.