Personally id steer clear of the pyramid huggers.. Seemed like the best option when i bought mine, as it covered the lower part of the shock, but i couldnt get it to sit properly and after 100miles or so it had started to rub on the tyre. Its currently collecting dust in the garage
As for the tail tidy, ive got a Hamicad on my K6 and love it! Took about 30mins to fit, is good quality and fits perfectly with the standard undertray
HTH