.com is best for company or commercial. But, if question is an non profitable organization, than .org is the best.
ALWAYS go for .com when it is available. It is what people always think of when typing your name. If both are available then get both and use 1 as a redirect or forward to the other. Now since you are already talking "selling" later then there is NO QUESTION that you NEED .com. Actually if you are selling then by having them both the buyer is going to be VERY pleased about this purchase as you have created higher perceived value.
This is a VERY Common misconception. Google does not care much between .com .net and .org. They are ALL TLD. Top Level Domains. If you have either more links, better SEO or better content you will ALWAYS beat someone with the same domain name regardless of who has whichever TLD. It is no different than having 1 $20 Bill or 2 $10 Bills. I guess the $20 looks better but they will both buy you the same thing.
.ORG was supposed to have trust of any organization but as anyone can get it even a student so .COM is the best choice these days.
I find .com is the best. >com will serve better than ever. It is easy to log in to a .com site. for the sites of .com you can use your keyboard as shortcut.
i forgot to say the shortcut.its ctrl+enter . please tell me anyone if there is any process to use shortcut for other like .org.