Memory query, pc-5300&5400

I'm looking for some RAM for a friend. I looked up her computer on Crucial and it said that each memory slot can hold DDR2 PC2-5300,DDR2 PC2-6400 with a maximum of 2GB per slot. I came across what looks like a a good deal from Tiger Direct on 2gb(2x1gb) OCZ System Elite Dual Channel PC5400 DDR2 667MHz Memory. But I'm kinda confused. Crucial said her computer will take pc5300 or pc6400, so would this pc5400 RAM be compatible? It seems like it would, but I really don't understand the technical details enough to be sure.

On a side note, I was wondering about dual-channel RAM. That OCZ RAM is labeled as dual channel, how is that different than regular memory? I thought any matching pair of RAM would work as dual channel, but are there some made specifically for that, which are different somehow?:confused

 

As far as I know the pc5400 is eactly the same as pc5300. The on;y thing the number difference means is that the manufacturer successfully tested that memory module at a higher speed.

About the dual channel i'm not too familiar.