Thank you nepali786 and - for your input; I will definitely give a serious consideration to hiring a lawyer. Hopefully some self-petitioners will also share their experiences here meanwhile.

I did consult (the free eval.) with wegreened.com folks - they were very responsive and recommended applying right now even though I'm few months away from getting my PhD.
Has anyone heard of or dealt with Taylor & Associates Law, PC? They are advertising "approval or no fee" for $2900 - one of the cheapest rates I've seen.