.

if you think you will upgrade it later on, ddr3. otherwise, ddr2.

Graphics card dude.....Graphics card

There is no difference between 800Mhz DDR2 and 1066DDR3.
The DDR3 has usually quite high timing yet making it slower.

In the range of the Intel processors you thinking about and they respective pricing the AMD Phenom II X2 550 would be faster at same price.
Just look around for benchmarks.