Kirwyn used to have a product (and freebie) called Genesis Hair.  It was fairly low-res.  I think about 300 polys.  He said that the problem with most dynamic hair is that most skullcaps were too high-res.  (Especially Poser 5 - skullcaps for dynamic hair got much lower-res after P5.  Like, by a factor of 10.)  One version of the Genesis Hair came with two skullcaps, so you could increase the density of the hair for closeups, if necessary.

It was meant for the Poser 5/6 era, or thereabouts, and worked really well for animation.  I did end up using a painted skullcap with it for closeups, though. 

I really like that hair, and still use it, but it doesn't work as well in Poser 9.  Both collisions and rendering are buggy, probably due to memory issues.  I've got 12 Gb of RAM, but apparently, that's not enough with Poser 9.  (Genesis Hair used to work beautifully with 1.5 Gb of RAM in Poser 5.)

I wish someone would make dynamic hair skullcaps.  The skullcaps available for prop hair are too high-res.  I'd like lower-res skullcaps, with high-quality textures (like 3Dream's universal skullcaps, only without that many polys).  Maybe different resolutions for different uses (animation vs. closeups).  And, like I said, with more polys along the hairline.