Hi rajeshrajk

What'd I recommend would be a test. Choose the one model that you think is going to be the most popular, register that domain and develop it well.

Within a couple of months you should be able to decide if you have a good idea on your hands. You can also use it as a platform for learning more about SEO. That way, even if this site doesn't work you'll have a much better chance of success with the next one.