I don't like head collars at all and unless you have to, I'd really opt not to use one. I've heard of too many accidents happening with them to feel safe using any. That, and when I did use one on Tango for a while I always felt really uncomfortable with it (and she didn't really like it much either - just tolerated it), especially when she'd turn her head suddenly to look at something. Have you thought of trying a no-pull harness? Those are supposed to work really well for pullers.

If you do choose to go for a head collar, which one is best really depends on your dog. You'd have to try both on him and see which fits better and such.