Patsy, regarding paddles for short boats; I used to do a lot of wave skiing years ago and the paddles had a 90degree feather and were fairly flat. the best on the market at the time were Brand X paddles. the wave skis were fairly short like a surf kayak, so timing and location in the take off zone are more import than paddling.
i now use very long surf skis. My current ski is 6.7Metres long which is about 22ft in the old money. Paddling is very important with the longer boat as you catch the wave differently by getting on to it as it is still starting to form. Acceleration and speed are all important with the longer boats as you try and match the speed of the swell (position on the wave is differnt as well). wing paddles are almost exclusively used here in Oz for the longer surf skis.
I think you could pretty much use any type of paddle with a bit of practice.
cheers