1333 bus any benefit without ddr3?

when buying ram and a motherboard if i buy a motherboard with a 1333 bus speed and i buy ram that is ddr2 800 pc6400 and overclock it to say 1066 i assume thats like having actual 1066 memory for less money but would it be better to just buy a higher rated memory from the start if price isnt to high? also if i have a 1333 bus how can i use that to its fullest potential without going ddr3? will the 1333 bus be of any use with ddr2 800 pc6400 or other ram? how does the extra bus speed benefit me for overclocking?

The 1066 FSB needs DDR2-533.
The 1333 FSB needs DDR2-667.

Be sure to get a P35 Mobo and you should be able to clock your FSB far beyond 1333FSB.

There is no point to DDR3 at this point.
It simply is not faster than DDR2 due to higher latency.

If getting a Q6600, there is no need for anything faster than DDR2-800.
Even w/o OCing the RAM, the CPU could hit 3.6Ghz which is an extremely nice OC for that Chip.

In fact, there is a good chance you will not want to OC it even that high.