I always get my purlside decreases confused, as to which ones slant which way. I just don't use them enough to remember!
I think you'd want to use p2tog to match a k2tog on the RS. And SSP (described on the decrease page), to match a left slanting RS decrease.....
KnittingHelp Queen Bee
It is not because things are so difficult that we do not dare; it is because we do not dare that they are difficult.