To answer all of your questions, I recommend the Kling on or Kling on empire over the Lucky Charm or Royale for Jackson boats. The way that Jackson cockpit rims are designed, a bungee skirt offers a much better and drier fit. The space between the combing and the boat itself is too small to fit a rand very well, especially the Royale due to the extra fabric. These skirts are very implosion resistant and I know numerous class 5 boaters who use the Kling On Empire especially. The only reason implosion could be a concern is if you have plans to run 30 plus foot drops. As for sizing, an XXL will fit the L Karma best, IMO.
When it comes to paddles, the Shogun is an excellent choice. The Shogun is a foam core paddle, so it is lightweight and the foam injected blades help with buoyancy. This translates to a better, stronger brace, and also helps with rolling as the paddle easily resurfaces. The dynel edge on the Shogun keeps the blade shape from wearing down like Powerhouse or Carbon Powerhouse will. They are pricey, but the foam core Werners are well worth the money.