The main difference between silks is the thickness (which is measured in momme). Pongee and Paj silk are very fine and light (often the same silk is called by one or the other of these names). They are great to get your drawing onto as you can see through them to the drawing beneath them as you draw with gutta on the silk.
Habutai is a thicker silk and is difficult to see through, so you may need to draw your design by placing the silk onto the drawing and completing with pencil before it is stretched on the frame.
Crepe de Chine is also thicker and will need to be drawn on with pencil before stretching. It also has a stretching quality and a texture. It is truly wonderful to work on and provides a great effect for a scarf. I use this silk for my framed paintings.