RAM timings can be very confusing, but a lot depends on your motherboard, CPU, and frequency of the Memory controller.
What MB are you using, and on the General Page of your BIOS, what is the Base Clock Frequency and what is the Memory controller set for?
It's probably 667 MHz and your standard 2 Channel RAM will be twice that.
The CAS is just the first number of the RAM timings as 9-9-9-24
Here is a good link that explains about all those numbers.http://www.hardwaresecrets.com/article/Understanding-RAM-Timings/26
Those new Vengeance RAM chips are very nice, run at 1.5V which is what most new memory controllers are spec'd at rather than the 1.65V most older RAM chips need. I haven't seen them in 8-8-8-24 configuration or faster yet but have seen them spec'd at 1600 MHz.
There was a short writeup about RAM frequency in Maximum PC magazine recently, and the concensus was the 1333 frequency was the sweet spot in relation to speed.