I do not recommend traveling with a "trunk" much less using public transportation to do so (unless you are the bionic woman). Ship your "trunk" to San Pedro and buy a good quality rolling case (the best kind is the soft pack with the removable packback, expensive but worth it.)
Do not take this kind of trip with any bag you cannot easily lift YOURSELF without hurting your back. With washable light clothing, its easy to do. Comfort is the most important thing for long trips. You need to be light on your feet to enjoy the kind of trip you envision.