hey, i just bought that board
what i've read is that dual channel won't make much of a difference in speed.
your a7n8x deluxe board can take 128MB to 1024MB in each of it's 3 memory banks. to use dual channel yo should use banks 2+3 which are colored blue to differentiate. i think you should get a single module of low latency pc3200 or pc2700 512MB memory for gaming.
that way if you decide to get more ram you will have room. i think with pc2700 and pc3200 you can only use 2 banks max but i may be wrong.