As far as domain names go as long as it is top level domain you could use about anything if you have great copy and a great products and great JV on your side.

Domain names are dime a dozen.

Unless you have $$$ to buy business.com or something make the domain name a secondary item.

Given enough link juice you can make anything rank well.

Get a dozen product ideas and do a survey on survey monkey to see if the idea is a go.

Weed out the no-go and take a good look at the go ideas. Now which one these ideas will give you the best return for your time.

Once you narrow it down to one just run with it and get it done.
Like the nike ads “Just Do It XXX Now.

Thanks
Charles Kirkland