The requirements for EB1 (EB1 Extraordinary Ability, and EB1 Outstanding Researcher or Professor) and NIW (EB2 National Interest Waiver ) are very different, and the application preparation is significantly different between these two classifications. For example, it may be likely that one could qualify for EB2 National Interest Waiver, but not qualify for EB1 Extraordinary Ability (EB-1A) and EB1 Outstanding Researcher or Professor (EB-1B). 

It is possible to file two petitions such as an EB1 and a NIW at the same time. Some applicants file two Form I-140 petitions simultaneously in EB1 and NIW. There is nothing stated in the law that prohibits multiple filings. Actually, multiple filings increase the chances of Form I-140 approval.

The EB1 Extraordinary Ability (EB-1A) and EB2 National Interest Waiver can be a self-petitioned application and does not need to be sponsored by a U.S. employer. But EB1 Outstanding Researcher or Professor (EB-1B) is an employer-sponsored application, it needs to be sponsored by your current employer. If you are currently employed, your employer’s sponsorship may help your application, including the letters of recommendation, and other evidences.