I think that unless you’re using a Thinkpad or Toughbook, you should invest in a padded sleeve for your laptop. The two laptops I described honestly are built to take some punishment, as they were meant for businessmen jumping around the world with or even taking to a construction site.
I actually use my old metal record box. You know, the ones everyone bought years ago that constantly got stolen in airports. I put my Xponent, laptop, cables, headphones, backup audio CDs, and even my MPD24 in there. Fits all nicely.
A case is fine, but I suggest a padded sleeve for the laptop. You can find them at any office supply store or computer store.