Weight may be an issue, but it would be the same in a cardboard box (give or take a pound). If it becomes a problem, I may look into shipping it separately.

I actually have a wheeled duffle already that I use for my clothing, and on my trip a year ago, when I had some boxed items (audio equipment mostly) but not as much, I did stick 'em in the duffle.

I'm reconsidering the plastic "storage footlocker" I saw earlier this week at K-Mart. I saw a wheeled version at the Container Store for $25, and K-Mart's without wheels is $20. A deciding factor between the two may be whether the wheelwell takes away space inside the trunk. They're made by the same company, Contico. I'm not worried about appearance. Contico says the trunk meets airline requirements (by 3/4 of an inch, I think and Postal Service requirements.