PERM 還是EB2/EB3?
PERM is the LC stage, after PERM approval, you will still need to go through I-140(EB2/EB3) stage. They are not an either/or option.
PERM and NIW(EB2-b) are either/or. You only need one to advance to the next step.
EB2 or EB3 LC depends on your position and job description. If it is not common requirement in your industry to hire master's degree for this position, you will need to explain why YOUR position needs a MA/MS worker.