I like shopdeals because its short and easy to remember, that imo is the key to any good domain. Customers can remember it and can type it out quickly without typos.
As for the ORG, you can always buy the COM/NET in the future once you get a decent demo site up and get VC funding for your startup.
As for marketing the ORG, some Customers may assume it is a non-profit or charity, but this might actually generate a lot of goodwill, especially if you say partial proceeds go to charity, and then Customers will grow because they like helping others.
You can still put up ads and e-commerce, just as long as you don't over-due it and make customers feel like its one of the same, instead of a site "trying to make a difference in the world"