There are literally thousands of online stores that sell software and parts. Have you already formed a corporation or an LLC, written up a business plan, and applied for necessary financing? What research have you completed? You're attempting to venture into heavily saturated territory. What unique feature do you bring to the table that others don't? Do you already have a web site set up?
I have to wonder since you're posting on a computer forum with the username "ineedhelpplease". This is a real business you're trying to establish. How prepared are you?
