I tried the configurator at Kingston for compatible RAMs, but I can't find the K55A.
You can try contacting Kingston and making sure that the RAMs are compatible.
"So, to refine my original post: IS a matchd (kit) 8gb 1600 cl9 the best I can do for this laptop w/o going into overclking and such? "
Answer: Yes, the board and the CPU support 1600 MHz.
The K55A specs:
DDR3 1600 MHz SDRAM, 2 x SO-DIMM socket for expansion up to 8 GB SDRAM