I needed a bigger toebox too, my LRS put me in a pair of Nike Zoom Vomero+ 5s. I really like them, but they might be too much shoe for your taste.

One thing you might try is roadrunnersports. com -- they have a shoe search, it helps you find shoes that might be a good fit for you.

It looks like the NB Minimus is scheduled for March 2011. Even though my "marathon career" is over, I'd be interested in seeing these.