All companies will tell you that the kit they sell is the best. However, I didn't want to buy something that I can find for free on the Internet such as the forms and "the correct address where to send the application".
I went to
www.usaia.org. They answered my questions within a few hours. I ordered the NIW case at night and received a link and a password to download a zip file the following morning. It's worth the money. Try it, you'll have a detailed example of what a succesful application looks like, and the person also added commentaries to guide you throughout the text.
I found greencardapply.com. I sent an email. If I am answered I'll let you know...
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