18,
These are two sets of our curriculum. Gam Gong Fuk Moh Kyun - Diamond Taming Demon Boxing, is also known as Gam Gong Fuk Fu Kyun or Daai Lik Gam Gong Kyun, within our family. Just different names for the same set. We use it as a beginner's set due to the relatively simple and short pattern and use of hard power. The set teaches the use of knees and elbows.
Fa Kyun is one of the sub-systems of our family. We have three sets. I have seen them quite a few times and discussed them with my teacher but do not train them myself. The fa kyun system focuses on fluidity of movement and uses the ng hang/five elements heavily.
Regards,
Justin