This is what someone told me about Chu Gar Gao and Chuka Shaolin Phoenix eye Fist

The Chuka you refer to is an older variant of Chu Gar Gao, practiced among the ethnic chinese of Malaysia (you have, i think, a copy of Donn F. Draeger's and Cheong Cheng-Leong). I can't really help you with the differences between it and Chu Gar Gao. However i recommend heavily an excellent resource off the Satbi site. (Click on the symbol in the upper left corner). It may take some searching but can be found under Southern Praying Mantis.
Other names for Variant's are Tong Long Jook Lum (not quite right, sorry), Hakka Fist, etc, depending on what lineage.