High Sierra seems to make something actually durable. My husband's wheeled duffel is over a decade old. He was using it for weekly trips between Denver and Washington DC when he was consulting there some years ago, and he doesn't travel as much anymore, but still uses it. It seems relatively water-resistant (not that we've submerged it or anything, but it didn't get anything inside wet when caught in the rain) and the wheels also seem very durable.

I'm not sure how you measure volume, but give them a look? http://www.ebags.com/category/luggag...rigin=left_nav However, if you NEED hardside, I'm not sure these will meet your needs.