I find that a company name and a domain name should fit the company and worry less about the SEO. With links, content, keywords, and blah blah blah. I have heard that age of domain and keywords in your domain are important.

The only issue with that is, if the keywords in your domain does not brand your domain with the people who are actually looking for your site, it becomes a mute point.

Look for a domain that represents your company and your customers will understand. Don't worry about Search engines so much.

what ever extension you use it works but is you use ; com : it optimize organically in google thats the advantage

TLD .com is always my preferred one. If my name is already taken with .com I'll then try it with .net. I rarely go with any other TLDs, because they are much less popular, unless I'm trying to reap the benefits from their true intention. For example, for starting an organization of some sort I would go with .org, etc.