The I140, which is the document to sponsor someone for the EB! is an employer based petition. You must either have your current employer or a new employer sponsor you. You cannot 'sponsor' yourself for a 'green card' unless you own the company.
EB1C would only be possible if your L-1A employer petitions you.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.