Why is being a Dictionary Word significant?
Typically, domains that consist of a single dictionary word and a top level domain have been registered for a significant amount of time. In the case of suitcase.org, the initial registration was some 18 years ago.
A single dictionary word cannot, on its own, be trademarked. Therefore there is no risk of a third party raising a dispute over inadvertent trademark violations.
Do your customers want to have to distinguish we-sell-you-suitcases from wesellsuitcases, or are you at risk from your customers being ensnared by selling-suitcases? Then a single, easy-to-remember domain is what you need.