Here is my 2-bits.
We have 3 spinnakers. Asymmetrical/Symmetrical/Gennaker.
We use the same pole for all three sails (four counting when we pole-out the 150% genoa). We use a Forespar spinnaker pole twist type extendable 6-12' (with the same hardware on both ends). We attach it to the mast on a 4' long vertical T-track, with s.s. car.
When using the Symmetrical spinnaker, I use the Asymmetrical tack-line (line run around a block on the bow and run aft) to stop the pole from lifting, and a topping lift from the mast that holds the pole up, horizontal to the foot/deck.
*to my knowledge;
The difference between a spinnaker pole and whisker pole, is the outboard hardware (end that attaches to the clew).
- A "Spinnaker Pole" attaches TO the sheet via a clip-type near the clew.
- A "Whisker Pole" has a point that goes THROUGH the sails clew-eye.
*note:
- There are also 2 differnt mast mounting harware options.
- A symmetrical spinnaker pole length should be approximately the length of the distance from base of mast to bow. On a

, that is about 10 feet.
- To pole-out (whisker) other sails (Asymmetrical/Gennaker/Genoa) I agree that length of the sails foot is correct.
Darry