You might try the
Inov-8 Trailroc 255 ... I have the 245s and they are quite toe-box-roomy (as 'natural' shoes tend to be), grippy (no good on wet wood, but solid everywhere else), and have a strong rock shield -- hours of running on many, many rocks last fall in the Megatransect and my feet were the least of my problems!! The 255s are even 'more so' -- mostly with the rock shield, I think, but they do have a 6mm drop vs. 3mm for 245s and 0mm for 235s.
I don't believe they have a 'rocker' sole, but the instep can take a pointy rock right in the middle without major flex or any real discomfort.
2014 model on sale for $75 at Wiggle!
http://www.wiggle.co.uk/inov-8-womens-trailroc-255... (bah, only a few sizes)