Which RAM is faster?


BF2 likes more ram, but otherwise, faster is better.
Because your chip runs at pc2700 speeds, and syncronous is better, stick with pc2700 speeds. Just the same, buy pc3200 ram, but run it at pc2700 speed.
About dual channel on your board. You have two slots for twinning, and one for dual channel. To have dual channel, the quantity of ram in the twins must be equal to the quantity of ram in the dual slot.
You can run pc3200 @ pc2700 speeds.