Of the three the Cold Sweat has the most bottom end. It can do Judas Priest (at least up to Ram It Down), early Metallica, early Slayer, Accept, KISS, late Thin Lizzy, Scorpions, and a heap of other classic metal sounds as well as punk stuff in an SG. Of the three it would probably be the best for palm-muting. The neck is very well suited to shredding, with a dark, round, fluid sound. Out of the three it would be the best for stuff like tapping.
Riff Raff is going to give you raunchy rock sounds of the '70s and can do a lot of heavier stuff as well, especially if you have a gutsy amp. If you have a little amp you might find it lacking a bit of bottom end in an SG. Overall though it is excellent. The neck is brighter than the neck in the other two sets. Think Angus Young.
The VHII would be a great middle ground between the two. It should be able to do most of what the other two sets could do.
The VHII and CS are more similar to one another than to the RR. The RR is more related to the Emerald and Rebel Yell and has a stronger emphasis on high mids.
The other thing is that 'punk' means different things to different people. If you are thinking more toward stuff like The Damned, then definitely the Riff Raff. If you are thinking Discharge I would go for one of the chunkier, more metal sounding pickups like the Cold Sweat. As I said the VHII represents a bit of a middle ground and I think could get you into both ballparks