You have a few options there. First off, you can use any bag or box, so you could just use any of the same kinds of containers you use in your bank vault. -OR- you can buy one or more of the new specialized sales containers made by carpenters and sold on the broker. These come in several flavors. You can get a dedicated container that wil hold a specific product (like weapons -or- armor -or- foor & drink -or- spells) or you can get a generic "salesman's crate" that will hold anything at all. btw - these new containers can be searched on the broker - there is a pre-set just for them.
The neat thing about these new containers is that they can be placed in your home like firniature and when you have done that, players can visit your home when you are off-line and buy directly from you saving the broker's fee. Since I put these in, I have seen a huge upswing in the sale of high end goods like rare tailored armor and rare bows & staves.