If you are going to use a consultant, the trick will be to know in advance whether s/he is any good, because after you've paid your money it is too late to change your mind.
There used to be a poster on this forum -- rjessome -- who had lots of practical knowledge, an who qualified as a consultant. Look for her previous posts and contact her, is my suggestion.
The difference between an immigration lawyer and an immigration consultant is about $1000 LOL.