Oh right, well, if you want to keep your current RAM then the new stuff will have to be the same speed anyway.
In short, you would be better off with the one I linked to, because you wouldn't be able to get the full speed out of the one you linked to, and you may get an unstable system.
If you wanted to get faster RAM with your new mobo, you could get
this, but it obviously costs more. You could sell your current RAM though, if you did want to get that one.