Not sure if this is what you are looking for
http://www.brookstone.com/rolling-ha...ctList|640854p

I own one, but don't use it for my laptop. Nice thing about it, it fits in overhead bin of E145/CRJ200.

For softside, where I carry my laptop, look at Tom Bihn. Expensive, but worth it in my opinion.
http://www.tombihn.com/travel_bags/TB0950.html

This one fits under seat, even well-loaded