Jumper settings on a Asrock 4Core1600Twins-P35 ?

Hi,
Im looking to upgrade my cpu later this year and as such i am trying to do my homework on how the jumper settings on my MoBo work exactly.
Now it has jumper settings for,
FSB 1066 with 1066 DDR2
FSB 1333 with 1066 DDR2
FSB 1600 with no mention of Ram at all.
There is another setting which i got from their website which was the answer in response to the question how can i get better overclocking with a FSB 800 CPU. This setting states that it puts the FSB and memory in a 1:1 Ratio.
I looked at just asking them but they want my inside leg measurement on the online form before they will even acknowledge i exist
So the question/s are what differance does the speed of the Ram make to the jumper settings ? Cant i still run the DDR2 800 that im using now if i decide to get a chip with a faster FSB ?
And also im wondering if the Ratio 1:1 setting would hold true for other chips at differant FSB speeds and as such i can leave well alone ?

Thanks
Mactronix