Hey CBC14K, I'm going to try to be a little more helpful than these dudes, even if I'm not in your exact same situation.
I currently use a 15" MBP with Kingston 2 x 4GB sticks that work flawlessly at 1600MHz. These sticks are proven to work consistently in every 15" MBP review (and never read of issues with other sizes either) I've ever seen.
Kingston also makes 2 x 4GB sticks that run at 1866MHz per second that are proven NOT to work consistently in MBPs. This is because these sticks run at case latency CL11, where the 1600MHz sticks run at CL9.
The point is, 1600MHz memory will work in your MBP and there is no reason to think it will be downclocked to 1333. As soon as you input the 1600MHz sticks, the System Report will immediately alter itself to read "Your computer accepts X number of stick at 1600MHz", where before it would read 1333.
As for KomputerBay, I say go for it. Like you say, it's not too expensive, it's (as far as I can tell) the only available 2 x 8GB set that is clocked at 1600MHz, and it's CL9 like the fully functional sticks that I'm using to type this message to you.
I think odds are in your favor, and not just because I want you to report success next week so I can order a set for myself... 😉
FYI if Kingston comes out with 2 x 8GB version of the following, buy it immediately: http://www.amazon.com/Kingston-Technology-1600MHz-KHX1600C9D3T1K2-8GX/dp/B004K32 QEG